Replace hidden KeyEvent.isMediaKey() usages

This CL copies the hidden KeyEvent.isMediaKey() method into
MediaController, and replace the usages with it.

Bug: 119789707
Test: mmm . (under frameworks/av/packages/MediaComponents)
Change-Id: I60e94c78f603378e5a4e3d54502cca1b36ef4d4e
2 files changed