Cannot deploy to a function hosted on Linux Consumption plan when AzureWebJobsStorage config setting is Key Vault reference

When a function hosted on Linux Consumption plan has AzureWebJobsStorage configuration setting set to valid Key Vault reference, errors block successful deployment via Az CLI and Functions CLI.

#### Investigative information

Please provide the following:

- Timestamp: 2021-03-26 04:06:00 UTC
- Function App version: ~3 runtime, dotnet-isolated (.NET 5)
- Function App name: oe-twitch-eus-identity-2021-03-15-func
- Function name(s) (as appropriate): N/A
- Invocation ID: N/A
- Region: East US

#### Repro steps

1. Create Function App using Linux Consumption plan
2. Enable Function System-Assigned Managed Identity
3. Create Azure Key Vault and grant Function App identity Secret List/Get permissions in Key Vault ACL
4. Add Key Vault secret containing the Function's Storage Account connection string as a value
5. Update the Function App AzureWebJobsStorage to be a Key Vault reference
6. Attempt to deploy a function app via Az CLI or Functions CLI.

#### Expected behavior

- Step 6 will successfully deploy the code to the Function App

#### Actual behavior

Az CLI fails with the following errors:

```bash
az functionapp deployment source config-zip -g OE-TWITCH-EUS -n oe-twitch-eus-identity-2021-03-15-func --src .\bin\publish\publish.zip
The command failed with an unexpected error. Here is the traceback:
You need to provide an account name and either an account_key or sas_token when creating a storage service.
Traceback (most recent call last):
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-taryuzhh\knack\cli.py", line 233, in invoke
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-sc_lkrar\azure\cli\core\commands\__init__.py", line 660, in execute
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-sc_lkrar\azure\cli\core\commands\__init__.py", line 723, in _run_jobs_serially
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-sc_lkrar\azure\cli\core\commands\__init__.py", line 716, in _run_job
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-l7ikczg1\six.py", line 703, in reraise
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-sc_lkrar\azure\cli\core\commands\__init__.py", line 694, in _run_job
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-sc_lkrar\azure\cli\core\commands\__init__.py", line 331, in __call__
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-sc_lkrar\azure\cli\core\__init__.py", line 808, in default_command_handler
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-ibh5mnup\azure\cli\command_modules\appservice\custom.py", line 385, in enable_zip_deploy_functionapp
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-ibh5mnup\azure\cli\command_modules\appservice\custom.py", line 543, in upload_zip_to_storage
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-r6yjb8kq\azure\multiapi\storage\v2018_11_09\blob\blockblobservice.py", line 146, in __init__
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-r6yjb8kq\azure\multiapi\storage\v2018_11_09\blob\baseblobservice.py", line 209, in __init__
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-r6yjb8kq\azure\multiapi\storage\v2018_11_09\common\_connection.py", line 110, in get_service_parameters
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-r6yjb8kq\azure\multiapi\storage\v2018_11_09\common\_connection.py", line 161, in _from_connection_string
File "C:\Users\VSSADM~1\AppData\Local\Temp\pip-unpacked-wheel-r6yjb8kq\azure\multiapi\storage\v2018_11_09\common\_connection.py", line 85, in __init__
ValueError: You need to provide an account name and either an account_key or sas_token when creating a storage service.
To open an issue, please run: 'az feedback'
````

Functions CLI fails with the following errors:

```bash
func azure functionapp publish oe-twitch-eus-identity-2021-03-15-func
Microsoft (R) Build Engine version 16.9.0+57a23d249 for .NET
Copyright (C) Microsoft Corporation. All rights reserved.

Determining projects to restore...
All projects are up-to-date for restore.
func-dotnet5 -> C:\Users\ryan\source\repos\func-dotnet5\bin\publish\func-dotnet5.dll
Determining projects to restore...
Restored C:\Users\ryan\AppData\Local\Temp\ure1mi1o.wlg\WorkerExtensions.csproj (in 1.14 sec).
WorkerExtensions -> C:\Users\ryan\AppData\Local\Temp\ure1mi1o.wlg\buildout\Microsoft.Azure.Functions.Worker.Extensions.dll

Build succeeded.
0 Warning(s)
0 Error(s)

Time Elapsed 00:00:08.79

Getting site publishing info...
Uploading package...
Error creating a Blob container reference. Please make sure your connection string in "AzureWebJobsStorage" is valid
Retry: 1 of 3
Error creating a Blob container reference. Please make sure your connection string in "AzureWebJobsStorage" is valid
Retry: 2 of 3
Error creating a Blob container reference. Please make sure your connection string in "AzureWebJobsStorage" is valid
Retry: 3 of 3
Error creating a Blob container reference. Please make sure your connection string in "AzureWebJobsStorage" is valid
````

#### Known workarounds

- Do not use a Key Vault reference for AzureWebJobsStorage setting on a Linux Consumption plan
- Use a Windows Consumption plan appears to work with AzureWebJobsStorage as Key Vault reference

#### Related information

Provide any related information

* Programming language used: .NET 5
* Links to source: N/A
* Bindings used: N/A