Update device registration helper methods for test fixes with local flight for keystore keys enabled, Fixes AB#3039504

[iamgusain]

Changes to fix tests for local flight run when keystore key flight is enabled. (Install cert operation is not supported separately with keystore keys flight enabled)

• When Authenticator is the active broker perform device registration with Authenticator settings UI instead of Device settings
• When adding account from Device settings page handle install cert UI only when it appears, (it doesn't appear when keystore keys flight is enabled, in that case just press ok to complete the action)

AB#3039504

[github-actions[bot]]

❌ Work item link check failed. Description does not contain AB#{ID}.

Click here to Learn more.

[github-actions[bot]]

✅ Work item link check complete. Description contains link AB#3039504 to an Azure Boards work item.

[somalaya]

Why would the test fail specifically when Auth app is the active broker? I mean why skip device reg from settings page in this case?