Merge "Remove unneeded 'slave' flag for /data_mirror/data_ce/null" am: 745111fb am: 779499ac

Original change: https://android-review.googlesource.com/c/platform/system/core/+/2271532



Change-Id: Ifd69b9104ddebb6b8c148588095193bd08c50edb
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>