Merge "Only allow the system server to connect to sync adapters" into qt-dev am: 99ccb4e5b0 am: 822fbf618b am: ea69ad5892 am: f15b3c2553

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/18701369

Change-Id: I1e1671c18a1573e819b76cbfb739d42cadc43aed
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>