Merge "Improve AllowedNetworkTypesForReason and refactor PreferredNetworkType" am: b332627a15

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/1614985

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: Ic767a18207a6f551ac49167c81c30e2f22793acf