Remove getter from PSBV animation method for dimming under the shade

Since we require a reboot to process high end graphics toggle on low end devices
there's no need to use a getter.  This method is processed a metric shit-ton of times
expanding/collapsing the shade.

PS2: missed a reference to isHighEndGfx()

Change-Id: Icf5af809e26fe79692c6185b51cc71deeb0aadde
ActivityManager: Rejigger HighEndGfx: only propget/stringcomp and resget once (in isHighEnd, rather than constructor)

Change-Id: I6ec977a9e8c7f46b186594c7bf6cad6a690121c9

Conflicts:
	core/java/android/app/ActivityManager.java
Memoize memory class lookup methods

These methods are commonly accessed.  Lets make sure we only do systemproperties lookup
once since these values aren't changing afterwords.

Change-Id: I77802ed367e4180f4d97e6abbd98170e6cf7a0d4

Conflicts:
	core/java/android/app/ActivityManager.java