Switch MST to use YAML pipeline for restarting app services

[angela-tran]

In #366, we defined a YAML pipeline for restarting the MST eligibliity-server app services.

Currently, we're not using it though because the pre-existing UI-configured pipeline under Pipelines > Releases was working fine.

SBMTD has been restarting its app services using the YAML pipeline all this time without problem, so let's switch over to using the YAML definition for MST as well. A benefit of doing so is that the "Restart app services" pipeline will appear in the same Pipelines section that the infra pipeline is in.

Steps in Azure DevOps:

• Disable the UI-configured pipeline
  

• Create a new pipeline that uses the YAML definition mst/azure-restart.yml

• Run it manually to verify it works

• Verify that scheduled runs work

[lalver1]

Thanks for your help and working with me on this one @angela-tran !

• Disable the UI-configured pipeline
• Create a new pipeline that uses the YAML definition mst/azure-restart.yml
• Renamed the new pipeline to Restart app services following SBMTD's naming convention
• Run it manually to verify it works
  • Verify that the restart occurred on the dev server and that it is running by using the /metadata endpoint
  • Verify that the restart occurred on the test server and that it is running by using the /metadata endpoint
  • Verify that the restart occurred on the prod server and that it is running by using the /metadata endpoint
• Verify that scheduled run works