Merge "Store preferential network service config in xml" into tm-dev am: 6d8f2732 am: 8a7f836c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/17643287



Change-Id: I0d7fb43f3c5cbb50d0c957d8bb3e35a0fb0a9a1a
Ignore-AOSP-First: this is an automerge
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>