Migrate cts/tests/tests/accounts to androidx.test

Also fork the common libraries like ctstestrunner to ctstestrunner-axt,
so cts can be converted to androidx.test incrementally instead of all at
once.

See go/jetpack-test-android-migration

Test: atest CtsAccountManagerTestCases
Change-Id: I1edff51013c4044791bf4fe4523365ffaa70ed54
118 files changed