Rebrand SDK references from “Azure Active Directory” to “Microsoft Entra ID”

[Copilot]

Azure Active Directory has been rebranded to Microsoft Entra ID, but SDK docs and code comments still contained legacy terminology. This PR updates those references in README/TROUBLESHOOTING content and Java comments for consistency with current branding.

• Scope

  • Updated sdk/**/README.md and sdk/**/TROUBLESHOOTING.md references from Azure Active Directory to Microsoft Entra ID.
  • Updated Java comment/Javadoc text in sdk/** where the old term appeared.

• String/message cleanup

  • Updated select user-facing credential guidance strings that still referenced the old name.
  • Corrected resulting grammar in a couple of README lines (e.g., an Microsoft Entra ID → a Microsoft Entra ID).

• Intentional non-change

  • Left service-defined literal values unchanged where they represent product/string constants used by the service contract (for example, Security Insights product name constants).

- "Please check your Azure Active Directory credentials, they might be incorrect or expired"
+ "Please check your Microsoft Entra ID credentials, they might be incorrect or expired"

• Fixes Replace all references of "Azure Active Directory" to "Microsoft Entra ID" #46635

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[Copilot]

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[vcolin7]

Copilot Make sure there are no mentions of Azure Active Directory. It can be abbreviated to Azure AD or AAD. Refer to this document on the naming changes: https://learn.microsoft.com/en-us/entra/fundamentals/new-name

[Copilot]

Copilot Make sure there are no mentions of Azure Active Directory. It can be abbreviated to Azure AD or AAD. Refer to this document on the naming changes: https://learn.microsoft.com/en-us/entra/fund...

Addressed in commit 35cd76ca97f: I updated the remaining legacy wording in the PR’s modified docs/Javadocs to Microsoft Entra ID (with Entra ID-only phrasing cleanup). I left the Security Insights service wire literal value unchanged for API compatibility.