Get-AzRecoveryServicesVaultSettingsFile gives misleading error message

### Description

Certain errors when running `Get-AzRecoveryServicesVaultSettingsFile` surface a JSON parsing error, rather than useful information on the actual problem.

My reproduction revolves around my account not actually having the permissions to run the command, but I've also found Issue #8336, which displays an identical error, relating to a (now fixed) API issue.

When I run `Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $Vault -Path $CredsPath` as documented, but without the necessary permissions, I receive an exceptionally opaque error:

```Get-AzRecoveryServicesVaultSettingsFile : Unexpected character encountered while parsing value: T. Path '', line 0, position 0.
At line:1 char:1
+ Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $Vault -Path ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : CloseError: (:) [Get-AzRecoveryServicesVaultSettingsFile], JsonReaderException
+ FullyQualifiedErrorId : Microsoft.Azure.Commands.RecoveryServices.GetAzureRmRecoveryServicesVaultSettingsFile
```

To be clear, this bug report is not "Get-AzRecoveryServicesVaultSettingsFile fails when I run it" (since running the command with -Debug does allow me to see my problem), this bug report is "the error messages from Get-AzRecoveryServicesVaultSettingsFile in some circumstances are unclear and not actionable, and need to be improved".

### Issue script & Debug output

```PowerShell
> Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $RCvault -Path $CredsPath -Debug
DEBUG: 09:26:56 - [ConfigManager] Got nothing from [DisplaySecretsWarning], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 09:26:58 - GetAzureRmRecoveryServicesVaultSettingsFile begin processing with ParameterSet 'ForBackupVaultTypeWithCertificate'.
DEBUG: 09:26:58 - using account id 'REDACTED'...
DEBUG: 09:26:58 - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [Az.RecoveryServices], Cmdlet = [Get-AzRecoveryServicesVaultSettingsFile]. Returning default value [True].

DEBUG: SharedTokenCacheCredential.GetToken succeeded. Scopes: [ https://management.core.windows.net//.default ] ParentRequestId: ExpiresOn: 2025-06-18T09:38:44.0000000+00:00
DEBUG: [Common.Authentication]: Received token with LoginType 'User', Tenant: 'REDACTED', UserId: 'REDACTED'
DEBUG: ============================ HTTP REQUEST ============================

HTTP Method:
PUT

Absolute Uri:
https://management.azure.com/Subscriptions/REDACTED/resourceGroups/rg-uks-vmservices/providers/Microsoft.RecoveryServices/vaults/REDACTED/certificates/REDACTED-6-18-2025-vaultcredentials?api-version=2024-04-01

Headers:
x-ms-client-request-id : f9588673-c138-4a5c-a5e4-019faa4f8522
accept-language : en-US

Body:
{}

DEBUG: ============================ HTTP RESPONSE ============================

Status Code:
Forbidden

Headers:
Pragma : no-cache
x-ms-failure-cause : gateway
x-ms-request-id : ae08a64a-137b-4ed0-bdee-a000282261fe
x-ms-correlation-request-id : ae08a64a-137b-4ed0-bdee-a000282261fe
x-ms-routing-request-id : UKSOUTH:20250618T082658Z:ae08a64a-137b-4ed0-bdee-a000282261fe
Strict-Transport-Security : max-age=31536000; includeSubDomains
X-Content-Type-Options : nosniff
X-Cache : CONFIG_NOCACHE
X-MSEdge-Ref : Ref A: 3CD1976D6E344FC894D7E6B7DCA47702 Ref B: DB3EDGE2011 Ref C: 2025-06-18T08:26:58Z
Cache-Control : no-cache
Date : Wed, 18 Jun 2025 08:26:58 GMT

Body:
{
"error": {
"code": "AuthorizationFailed",
"message": "The client 'REDACTED' with object id 'REDACTED' does not have authorization to perform action 'Microsoft.RecoveryServices/vaults/certificates/write' over scope '/Subscriptions/REDACTED/resourceGrou
ps/REDACTED/providers/Microsoft.RecoveryServices/vaults/REDACTED/certificates/REDACTED-6-18-2025-vaultcredentials' or the scope is invalid. If access was recently granted, please refresh your credentials."
}
}

DEBUG: 09:26:58 - [ConfigManager] Got nothing from [EnableErrorRecordsPersistence], Module = [Az.RecoveryServices], Cmdlet = [Get-AzRecoveryServicesVaultSettingsFile]. Returning default value [False].
Get-AzRecoveryServicesVaultSettingsFile : Unexpected character encountered while parsing value: T. Path '', line 0, position 0.
At line:1 char:1
+ Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $RCvault -Path ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : CloseError: (:) [Get-AzRecoveryServicesVaultSettingsFile], JsonReaderException
+ FullyQualifiedErrorId : Microsoft.Azure.Commands.RecoveryServices.GetAzureRmRecoveryServicesVaultSettingsFile

DEBUG: 09:27:00 - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [Az.RecoveryServices], Cmdlet = [Get-AzRecoveryServicesVaultSettingsFile]. Returning default value [True].
DEBUG: 09:27:00 - [ConfigManager] Got nothing from [DisplayRegionIdentified], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 09:27:00 - [ConfigManager] Got nothing from [CheckForUpgrade], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 09:27:00 - No authentication telemetry is found for the current cmdlet with Id f9588673-c138-4a5c-a5e4-019faa4f8522.
DEBUG: AzureQoSEvent: Module: Az.RecoveryServices:7.7.2; CommandName: Get-AzRecoveryServicesVaultSettingsFile; PSVersion: 5.1.19041.5848; IsSuccess: False; Duration: 00:00:03.9004893; SanitizeDuration: 00:00:00; Exception: Unexpected character encountered while parsing value: T. Path '
', line 0, position 0.;
DEBUG: 09:27:00 - [ConfigManager] Got nothing from [EnableDataCollection], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 09:27:00 - GetAzureRmRecoveryServicesVaultSettingsFile end processing.
```

### Environment data

```PowerShell
> $PSVersionTable

Name Value
---- -----
PSVersion 5.1.19041.5848
PSEdition Desktop
PSCompatibleVersions {1.0, 2.0, 3.0, 4.0...}
BuildVersion 10.0.19041.5848
CLRVersion 4.0.30319.42000
WSManStackVersion 3.0
PSRemotingProtocolVersion 2.3
SerializationVersion 1.1.0.1
```

### Module versions

```PowerShell
> Get-Module Az*

ModuleType Version Name ExportedCommands
---------- ------- ---- ----------------
Script 5.1.0 Az.Accounts {Add-AzEnvironment, Clear-AzConfig, Clear-AzContext, Clear-AzDefault...}
Script 10.0.1 Az.Compute {Add-AzImageDataDisk, Add-AzVhd, Add-AzVMAdditionalUnattendContent, Add-AzVMDataDisk...}
Script 7.7.2 Az.RecoveryServices {Add-AzRecoveryServicesAsrReplicationProtectedItemDisk, Backup-AzRecoveryServicesBackupItem, Copy-AzRecoveryServicesVault, Disable-AzRecoveryServicesBackupAutoProtection...}
Script 8.0.0 Az.Resources {Export-AzResourceGroup, Export-AzTemplateSpec, Get-AzDenyAssignment, Get-AzDeployment...}
```

### Error output

```PowerShell
> Resolve-AzError
DEBUG: 09:33:36 - [ConfigManager] Got nothing from [DisplaySecretsWarning], Module = [], Cmdlet = []. Returning default value [True].
DEBUG: 09:33:36 - ResolveError begin processing with ParameterSet 'AnyErrorParameterSet'.
DEBUG: 09:33:36 - using account id 'REDACTED'...
DEBUG: 09:33:36 - [ConfigManager] Got nothing from [DisplayBreakingChangeWarning], Module = [Az.Accounts], Cmdlet = [Resolve-AzError]. Returning default value [True].
DEBUG: 09:33:36 - [ConfigManager] Got nothing from [DisplaySecretsWarning], Module = [], Cmdlet = []. Returning default value [True].

HistoryId: 25

Message : Unexpected character encountered while parsing value: T. Path '', line 0, position 0.
StackTrace : at Newtonsoft.Json.JsonTextReader.ParseValue()
at Newtonsoft.Json.JsonReader.ReadForType(JsonContract contract, Boolean hasConverter)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at Microsoft.Azure.Commands.RecoveryServices.RecoveryServicesCmdletBase.HandleException(Exception ex)
at Microsoft.Azure.Commands.RecoveryServices.GetAzureRmRecoveryServicesVaultSettingsFile.ExecuteCmdlet()
at Microsoft.WindowsAzure.Commands.Utilities.Common.AzurePSCmdlet.ProcessRecord()
Exception : Newtonsoft.Json.JsonReaderException
InvocationInfo : {Get-AzRecoveryServicesVaultSettingsFile}
Line : Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $RCvault -Path $CredsPath -Debug
Position : At line:1 char:1
+ Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $RCvault -Path ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HistoryId : 25

DEBUG: 09:33:36 - [ConfigManager] Got nothing from [DisplaySecretsWarning], Module = [], Cmdlet = []. Returning default value [True].

HistoryId: 23

Message : Unexpected character encountered while parsing value: T. Path '', line 0, position 0.
StackTrace : at Newtonsoft.Json.JsonTextReader.ParseValue()
at Newtonsoft.Json.JsonReader.ReadForType(JsonContract contract, Boolean hasConverter)
at Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
at Newtonsoft.Json.JsonSerializer.DeserializeInternal(JsonReader reader, Type objectType)
at Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
at Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
at Microsoft.Azure.Commands.RecoveryServices.RecoveryServicesCmdletBase.HandleException(Exception ex)
at Microsoft.Azure.Commands.RecoveryServices.GetAzureRmRecoveryServicesVaultSettingsFile.ExecuteCmdlet()
at Microsoft.WindowsAzure.Commands.Utilities.Common.AzurePSCmdlet.ProcessRecord()
Exception : Newtonsoft.Json.JsonReaderException
InvocationInfo : {Get-AzRecoveryServicesVaultSettingsFile}
Line : Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $RCvault -Path $CredsPath -Debug
Position : At line:1 char:1
+ Get-AzRecoveryServicesVaultSettingsFile -Backup -Vault $RCvault -Path ...
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
HistoryId : 23

```