ci: add angular robot config file (#21489)

PR Close #21489

.github/angular-robot.yml

@@ -0,0 +1,52 @@
+# Configuration for angular-robot
+
+# options for the merge plugin
+merge:
+  # the status will be added to your pull requests
+  status:
+    # set to true to disable
+    disabled: false
+    # the name of the status
+    context: "ci/angular: merge status"
+    # text to show when all checks pass
+    successText: "All checks passed!"
+    # text to show when some checks are failing
+    failureText: "The following checks are failing:"
+
+  # comment that will be added to a PR when there is a conflict, leave empty or set to false to disable
+  mergeConflictComment: "Hello? Don't want to hassle you. Sure you're busy. But this PR has some merge conflicts that you probably ought to resolve.
+\nThat is... if you want it to be merged someday..."
+
+  # label to monitor
+  mergeLabel: "PR action: merge"
+
+  # list of checks that will determine if the merge label can be added
+  checks:
+    # whether the PR shouldn't have a conflict with the base branch
+    noConflict: true
+    # list of labels that a PR needs to have, checked with a regexp (e.g. "PR target:" will work for the label "PR target: master")
+    requiredLabels:
+      - "PR target:"
+      - "cla: yes"
+
+    # list of labels that a PR shouldn't have, checked after the required labels with a regexp
+    forbiddenLabels:
+      - "PR target: TBD"
+      - "cla: no"
+
+    # list of PR statuses that need to be successful
+    requiredStatuses:
+      - "continuous-integration/travis-ci/pr"
+      - "code-review/pullapprove"
+      - "ci/circleci: build"
+      - "ci/circleci: lint"
+
+    # the comment that will be added when the merge label is added despite failing checks, leave empty or set to false to disable
+    # {{MERGE_LABEL}} will be replaced by the value of the mergeLabel option
+    # {{PLACEHOLDER}} will be replaced by the list of failing checks
+    mergeRemovedComment: "I see that you just added the `{{MERGE_LABEL}}` label. It won't do anything good though, because the following checks are still failing:
+  \n{{PLACEHOLDER}}
+  \n
+  \n**If you want your PR to be merged, it has to pass all the CI checks.**
+  \n
+  \nIf you can't get the PR to a green state due to flakes or broken master, please try rebasing to master and/or restarting the CI job. If that fails and you believe that the issue is not due to your change, please contact the caretaker and ask for help."