Extend forced hardware acceleration support to highend gfx

If property persist.sys.ui.hw is set to true, bypass free memory check
for hardware acceleration of "highend gfx" in ActivityManager.

Change-Id: I0dff2ab9f9e37e5c27d37220747181dfb86fbb5f

Conflicts:
	core/java/android/app/ActivityManager.java
Fix build: QCOM_ICS_COMPAT
 * Dont know why i can't cherry-pick:
   https://github.com/androidarmv6/android_frameworks_base/commit/f5b2c8874173c5c5cefe7ab4171c650526b3a3aa