ActivityTrigger:  New class to invoke when activity starts/resumes

Conflicts:
	services/java/com/android/server/am/ActivityStack.java

Change-Id: Ib57aa4d3767e27b5bba658b27e084fc3ef042c36
power: Add CPU boosting interface

 * Boosts CPU using Power HAL for the given duration.
 * Duration is given in microseconds.
 * Power HAL must implement POWER_HINT_CPU_BOOST.

Change-Id: Ic79baf7e3d0f75483c2fe8a242b4c3d93368b68b
Merge changes Ic79baf7e,Ib57aa4d3 into jb4.3

* changes:
  power: Add CPU boosting interface
  ActivityTrigger:  New class to invoke when activity starts/resumes