Add Jetpack Compose example to CI

[Kernald]

This PR shows a few issues with the Jetpack Compose example:

• It's not built on CI
• It actually doesn't build.

But also with the overall example structure. There seem to be a hook set-up on CI to use a release build of the rules, which obviously doesn't work when building locally. The problem is, when using the parent repo, specifying a compiler_release in kotlin_repositories doesn't seem to work (not entirely sure why).

While this might end up building on CI (edit: it doesn't) with the few changes here, it definitely does not build locally as Compose 1.0.0-alpha09 requires kotlinc 1.4.21, which there's no way to force with the current set-up locally - the default version is 1.4.20.

[Kernald]

cc @Bencodes who initially wrote the sample

[restingbull]

Ah. We've been release blocked because we all thought we'd mucked up our dev boxes.

[Kernald]

I'm not sure why jarjar_runner fails to run on CI, as it runs perfectly on my machine in the same context.

[Kernald]

One of the issues raised here is fixed by #530.

[cgruber]

Hey @Kernald - mind resolving this or rebasing against master, and we can look again and see what's going wrong?

[Kernald]

I'll rebase and update as necessary tomorrow or Monday and ping here once it's done!

[Kernald]

@cgruber This is now rebased onto master, with a bit of clean-up to make buildifier happy, and fails with the same error in CI (it builds just fine locally on my machine).

I also tried to update Compose to its latest (1.0.0-rc01) version, which starts failing locally (most likely due to bazelbuild/bazel#13553, not related to rules_kotlin afaik).

[Bencodes]

@Kernald I opened up a new PR with everything fixed over here #657

[Kernald]

Thanks, I'll have a look later this weekend/early next week!

[restingbull]

Superseded by #657