Adding aconfig flag: mount_before_data am: bc117db3f3

Original change: https://android-review.googlesource.com/c/platform/system/apex/+/3526391

Change-Id: Ibfec1cf1d6ecdbdf94780e0adb2f5374779a834e
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>