Disabled MSI tests due to instance discovery changes in MSAL for MSI

This work item is to track the currently disabled test:
- ManagedIdentityWithFic_WithClaims_BypassesCache 
- ManagedIdentity_WithClaims_HeaderBypassesCache
- UserAssigned_MI_Caching_and_Claims
- ManagedIdentity_ReturnsBearerHeader 
- SystemAssigned_MSI_Forwards_ClientCapabilities_InQuery 

These tests is disabled due to changes in Managed Identity instance discovery in MSAL.