rewrite android_app to android_test in mk2bp

1. When a converted android_app module has the `test_suites` property,
rewrite the module type to an android_test one;
2. Refactor the existing codes for rewriting cc_binary to cc_test.

Bug: 217650002
Test: add unit and end-to-end tests
Test: TreeHugger
Change-Id: I90d744a2ae93561f63ed8606f37ea4aa26fa6137