Add build test for Flutter codelabs (#19579) * Add build test for Flutter codelabs * Fix indentation in build test script * Correct filename for the codelabs build test run by travis * Change if statement to elif * Replace echo statements with set -x * Add BSD-style license * Add codelabs build test to Cirrus * Remove codelabs_build_test from Travis. * Remove codelabs_build_test from travis_script.sh * Update documentation for codelabs_build_test.sh * Update readme for build test * Add link to open a new issue to MDC-Flutter * Add phrase to address "if you think you really need to break this test, please escalate this"

diff --git a/dev/bots/README.md b/dev/bots/README.md
index a340fd1..19ca89d 100644
--- a/dev/bots/README.md
+++ b/dev/bots/README.md

@@ -148,3 +148,17 @@
 6. Run upload_android_tools.py -t ndk
    `$ cd ../..`
    `$ dev/bots/upload_android_tools.py -t ndk`
+
+## Flutter codelabs build test
+
+The Flutter codelabs exercise Material Components in the form of a demo application. Note that the 
+code for the codelabs is similar to but distinct from the code for the Shrine demo app in Flutter Gallery.
+The Flutter codelabs build test ensures that the final version of
+[Material Components for Flutter Codelabs](https://github.com/material-components/material-components-flutter-codelabs)
+can be built. This test serves as a smoke test for the Flutter framework and should not fail. Please
+address the issue from within your PR and rerun the test. If you feel that the test failing is not a
+direct result of changes made in your PR or that breaking this test is absolutely necessary, escalate this issue by
+[submitting an issue](https://github.com/material-components/material-components-flutter-codelabs/issues/new?title=%5BURGENT%5D%20Flutter%20Framework%20breaking%20PR)
+to the MDC-Flutter Team.
+
+