BoostFramework to enhance performance during critical scenarios

Adding Boost APIs which can ensure the best possible resource
availability during critical UX scenarios. These APIs can be
either turned off or dynamically hooked to OEM specific
performance optimizations

Squashed with change: I90a733d7134d86efffadf6815ce3d2944dd09419

Performance: Make Cached apps limit configurable.

Set it via a target specific property
file. Allows flexibility to set the limit
based on device config

Normally, setting a smaller value for
low-end device helps with performance.

Conflicts:
	core/res/res/values/symbols.xml

Change-Id: I51a83708d145ab8fd780b10c33d40db1291d6edd