tuna: use mheap screenshots

Change-Id: I14bd7ada35aefb493cb5c275247bf61b5a5faba5
Fix rotation and CRT-off animation glitches

Use -DFORCE_SCREENSHOT_CPU_PATH and
disable Zygote preload of EGL drivers

Refer to:
https://github.com/CyanogenMod/android_frameworks_native/commit/b2150f9

Change-Id: I126fb00d8701389a0cd401a49006dce469c0fd91