QCamera2: set snapshot format to YUV422 when system prop is set
QCamera2: set snapshot format to YUV422 when system prop is set

Per test request, when system prop "persist.camera.snap.format" is
set to 1, snapshot format should be set to YUV422.

CRs-Fixed: 462490

Change-Id: Idd353f90338b595096622bebbeda59a46e578693

maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead,maruos/android_device_lge_hammerhead