HALO: Option to pause the underlying app (1/2)

- adds an option to pause the active app when using HALO
- this is enabled by default for devices with low memory
- (currently: <640MB RAM available to the kernel)

Conflicts:
	core/java/android/provider/Settings.java

Change-Id: Id95410f7b9f03f6ebd1fbe4aa9a379ae3b0b8edf