[Security] AdvancedThreatProtection_Get returns out of date value

the `get` operation returns old value some times after an `AdvancedThreatPRotection_Create` called some times.

e.g.:
request1: `AdvancedThreatProtection_Create` with `isEnabled` set to `false`
request2: `AdvancedThreatProtection_Create` with `isEnabled` set to `true`
request3: `AdvancedThreatProtection_Get` on the same resource, we might get `false`

swagger path: https://github.com/Azure/azure-rest-api-specs/blob/main/specification/security/resource-manager/Microsoft.Security/stable/2019-01-01/advancedThreatProtectionSettings.json

Start with specification/security/resource-manager/Microsoft.Security/stable/2019-01-01/advancedThreatProtectionSettings.json and compare the documented AdvancedThreatProtection_Create and AdvancedThreatProtection_Get operations. The report describes a possibly stale service response but does not identify a repository change, test, or clear definition of done; confirm whether the API specification can represent the issue before proceeding.

Written by the indexing model from the issue text.