AI 143177: am: CL 142889 Fix issue #1736153 Camera shutter sound can be muted...

AI 143177: am: CL 142889 Fix issue #1736153	Camera shutter sound can be muted by new AlarmClock setting.
  Current implementation of Camera service plays the camera shutter sound over the ALARM stream so that it cannot be muted by silent mode in order to comply to some country specific requirement. A recent change made it possible for the user to mute the ALARM stream thus making this stream not suitable any more for the camera shutter sound.
  The fix consists in creating a new stream type only accessible by native code and that cannot be muted and use it to play camera sounds.
  Original author: elaurent
  Merged from: //branches/cupcake/...

Automated import of CL 143177