Merge changes I45bf0300,Ib30324ae,I409dc02d,I5096786e,I9dccd0b4, ...

* changes:
  Build libbluetooth_jni as a multi-lib
  Clean up some files that appear to be unused
  Remove now unused room libraries
  Migrate bluetooth unit tests Android.mk file to bp
  Move jni/Android.bp into Android.bp
  Migrate Bluetooth.apk to Android.bp