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
Derp bracket fixes for 'Fix volume key music controls and wake up'
SystemUI: status bar brightness: store value as int

Non-automatic brightness value is stored as int, not float.

Symptom: adjust the brightness in the status bar, the brightness
         slider in the notification bar will always be set to full

Change-Id: I5f9a6e97bae2c44c3aff7c9222186a6dbda5d902