Add `android_ravenwood_test` build rule

Since we're unable to compile libcore classes for the device,
we temporarily pivot usages to our own copy of EmptyArray.

Bug: 292141694
Test: m nothing --no-skip-soong-tests
Test: m hoststubgen ravenwood-runtime tradefed atest && atest-dev HostStubGenTest-framework-test
Change-Id: I9d4ff559924e47725eb3e897aaf2cc93e9b1a193