enforce camera sound according to country code

Use mcc config overlay mechanism to enforce camera shutter sounds
in countries where it is mandatory.
Property ro.camera.sound.forced is not needed anymore.
When camera sound is forced, STREAM_SYSTEM_ENFORCED is removed from
streams affected by ringer mode and its volume is
maxed out. AudioSystem.FORCE_SYSTEM_ENFORCED is sent to audio
policy manager to alter the routing policy for STREAM_SYSTEM_ENFORCED.

Also fix streams being unmuted when settings are reloaded
upon user switch while in silent mode.

Add ringer mode to audio service dump.

Bug 7032634.

Change-Id: Iceea5bba3b8d3aabf8e42b222deb33a893dc8f38