set subscription id and tenant id in telemetry if it's null

[YanaXu]

It's for Content-AzAccount. When it's run, the subscription id and tenant id is not set in context. That's why they are empty in telemetry.
This PR is going to set them before recording the telemetry.

[isra-fel]

PR itself looks good.
If we do this, does it make the logic of setting sub id in AzureRMCmdlet.BeginProcessing duplicate, and can we remove that?
Also, this will impact cmdlets that do not inherit AzureRMCmdlet . Please ensure we have tested that scneario. Thanks.

[YanaXu]

PR itself looks good. If we do this, does it make the logic of setting sub id in AzureRMCmdlet.BeginProcessing duplicate, and can we remove that? Also, this will impact cmdlets that do not inherit AzureRMCmdlet . Please ensure we have tested that scneario. Thanks.

@isra-fel , according to your comment, I changed the update and test the below cmdlets. Their subscription ids and tenant ids are recorded correctly now.

• Get-AzAksCluster
• Get-AzConfig
• Get-AzDatabricksWorkspace
• Get-AzContainerApp
• Get-AzEnvironment
• Get-AzContext
• Get-AzAccessToken
• Get-AzSqlVM
• Connect-AzAccount

[isra-fel]

Need more time to check if it's safe to remove RequireDefaultContext. Will catch up next week

[isra-fel]

@YanaXu can you test running some cmdlets that doesn't require a context after clearing the context? They should still work without a context.
Examples are the *DataCollection and ContextAutoSave cmdlets.

[isra-fel]

PR looks good if we verified the above cmdlets