Audio policy manager changes for audio effects

Added methods for audio effects management by audio policy manager.
- control of total CPU load and memory used by effect engines
- selection of output stream for global effects
- added audio session id in parameter list for startOutput() and stopOutput().
this is not used in default audio policy manager implementation.

Change-Id: I3467e64035387cc5272266b1318a5ed788958374
2 files changed