Keep quiet when volume keys are used to wake up device

- Userspace will make a 'beep' with it receives a key up, so
  consume that event as well.
- Removed wake key check in music control code as it will already
  be disabled here.

Change-Id: I93839acd39aec8a2ee40291f833a31f6b048c9f8

Patchset: 5
http://review.cyanogenmod.org/#/c/82350/
(cherry picked from commit 37de825e7e35c2352f4b36425bb5d32523fd29dc)