Revert "Fix forceHighEndGfx property to override isHighEndGfx"

This reverts commit b63333c61ee9c94a7258abbdb73d886d0602b01d.

Conflicts:
	res/xml/development_prefs.xml
	src/com/android/settings/DevelopmentSettings.java

Change-Id: I2a4748b51ed6aa2c2f4ebe4faef7e4f72c3a6c36