Update the CI build to only run p0 UI tests for PRs and all UI tests for rolling CI builds (#1012)

* Added testcasefilter to the UI tests yaml

* Set priorities on UI tests

* Add UI tests for PRs yaml file, conditionally add it to the CI build yaml

* Update priority on functional tests

* Use a conditional task input instead of an additional yaml file to determine if UI tests should be filtered to P0 only

* Add condition:succeeded() back into the run-ui-tests.yaml

* Add back line

Co-authored-by: Matt Cooley <matt@mattcooley.net>

build/pipelines/templates/run-ui-tests.yaml

@@ -47,4 +47,6 @@ jobs:
       vsTestVersion: 16.0
       runSettingsFile: $(Build.ArtifactStagingDirectory)/drop/Release/${{ parameters.platform }}/publish/${{ parameters.runsettingsFileName }}
       platform: ${{ parameters.platform }}
-      configuration: Release
+      configuration: Release
+      ${{ if eq(variables['Build.Reason'], 'PullRequest') }}:
+        testFiltercriteria: Priority=0