Use KitKat zRAM setting

CM's compcache has been removed, so we need to migrate to KitKat's mechanism. The value is set to 128 MB for now. This gets compressed to ~40 MB on RAM and may provide benefits to multitasking.

From:
https://github.com/CyanogenMod/android_device_samsung_aries-common/commit/92e93e8bf0058d526302b2762a8b40debc218ac7
https://github.com/CyanogenMod/android_device_samsung_aries-common/commit/6c337320aafdc23c23dc2b0cb92279a06ee28b30