Introduce smoke tests in CI for instrumentation targets

[FareesHussain]

Add CI check to check if the targets will build successfully.

#3505 (comment) For details.

[FareesHussain]

@BenHenning I'm wondering what rule to use here.

like you've mentioned #3505 (comment) here that we need something like

bazel test //instrumentation:build_instrumentation_targets

to check these.

To me it looks like a target that contains all the targets we need to build in the CI for these smoke tests.

but instead can't we just do bazel build //instrumentation:all here.
in this case we can also shift the oppia_test to the instrumentation package as in the 2.3 pr we need it to access a separate AndroidManifest.

[BenHenning]

@BenHenning I'm wondering what rule to use here.

like you've mentioned #3505 (comment) here that we need something like

bazel test //instrumentation:build_instrumentation_targets

to check these.

To me it looks like a target that contains all the targets we need to build in the CI for these smoke tests.

but instead can't we just do bazel build //instrumentation:all here. in this case we can also shift the oppia_test to the instrumentation package as in the 2.3 pr we need it to access a separate AndroidManifest.

Didn't address this originally, but the main reason we can't use 'all' is by introducing a smoke test, we actually turn a build verification check into a test (i.e. one that's picked up by bazel test) which means it will be included in the possible output from ComputeAffectedTests. This is ideal since it ensures verification of these builds happens automatically in the current CI configuration and happens only when necessary (i.e. instrumentation dependencies change).