YAML pipeline creation error workaround

The creation of new YAML pipelines is now functional across all geographies. The issue is fully mitigated. Our engineers identified an issue introduced related to Xamarin end of support work ([more information here](https://dotnet.microsoft.com/en-us/platform/support/policy/xamarin))

Our sincere apologies for any inconvenience this issue may have caused. We will do our best to learn from it and prevent future reoccurrences.

Issue has been mitigated in most geographies. However, it still remains active for some organizations in west US region. We recommend impacted customers to use the workaround options provided, while the fix gets rolled out completely.
We apologize for any inconvenience this issue might have caused.

A subset of customers in certain geographies might encounter this error when trying to create a new YAML pipeline: "No template with an identifier of ‘xamarinandroid’ could be found". While the fix for the issue is being rolled out, here are the workaround options:

**[recommended, if possible, always go with this approach]** Use the Pipeline creation REST API to create a new pipeline (see https://learn.microsoft.com/en-us/rest/api/azure/devops/pipelines/pipelines/create?view=azure-devops-rest-7.1) After creating it, you can continue editing in UI.

**[if the first approach is definitely not applicable]** Or through the UI:
1. Disable the setting "Disable creation of classic build pipelines" on Organization/Project-level pipeline settings:
2. In pipeline creation UI, choose "Use the classic editor":
3. Select the source repository, hit "Continue"
4. Choose YAML as the template:
5. Choose a YAML definition (if any exists). If you don't have any, create an empty YAML file in the repository.
6. Save the pipeline. You now have a new pipeline, if you click on "Edit", you can continue editing your pipeline in the regular YAML experience. **Important**: Set the switch back to its original state after the rollout is completed (ETA February 24).

We apologize for any inconvenience this issue might have caused.

A subset of customers in certain geographies might encounter this error when trying to create a new YAML pipeline: "No template with an identifier of ‘xamarinandroid’ could be found". While the fix for the issue is being rolled out, here are the workaround options:

**[recommended, if possible, always go with this approach]** Use the Pipeline creation REST API to create a new pipeline (see [https://learn.microsoft.com/en-us/rest/api/azure/devops/pipelines/pipelines/create?view=azure-devops-rest-7.1]()) After creating it, you can continue editing in UI.

**[if first approach is definitely not applicable]** Or through UI:
1. Disable the setting "Disable creation of classic build pipelines" on Organization/Project-level pipeline settings
2. In pipeline creation UI, choose "Use the classic editor"
3. Select the source repository, hit "Continue"
4. Choose YAML as the template
5. Choose a YAML definition (if any exists). If you don't have any, create an empty YAML file in the repository.
6. Save the pipeline. You now have a new pipeline, if you click on "edit", you can continue editing your pipeline in the regular YAML experience.
**Important**: Set the switch back to its original state after the rollout is completed (ETA February 24).

We apologize for any inconvenience this issue might have caused.