Merge "Allow settings app to request pin appwidgets from other apps." into udc-qpr-dev am: 732bb20f am: 2bf9417a

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/24933432



Change-Id: I02c99e70f292818ba4cdf4b001b30356311c53a6
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>