Ravenwood reafatoring

Move all the tests to the `com.android.ravenwoodtest` package in order
to tell them part from actual ravenwood code.

This allows various tools to ignore ravenwood code without ignoring
ravenwood test code.

Test: ./ravenwood/scripts/run-ravenwood-tests.sh
Bug: 292141694

Change-Id: I48728784e7dd2e5aea3327da793923c8ef3b795d