Make art_debug_defaults inherit art_defaults.

To take art_defaults closer to a true global defaults used by
everything in the ART module. This also means we unify the compiler
flags for various debug-only things that didn't inherit art_defaults
explicitly.

#codehealth

Test: Run-tests, gtests, libcore tests and libjdwp tests for host and
  device on master-art
Bug: 204364566
Change-Id: Ic76093f104169fc9178c6b6acca6db23d643f9ec