staging: android: lowmemorykiller: update from android-3.4

Change-Id: I54c8aa9813999d11660737474526dcd9a90dccf5
staging: android: lowmemorykiller: port zram for android and enhanced lmk routine

Change-Id: I84b850e3702cc615004d5e4ae2c5da81e27b6f51
staging: android: lowmemorykiller: backport caf updates

Change-Id: Id40e300bf266d8e2f0dc41fd8d77c2546ef432eb