Merge "Notify content capture on detach before setting attachInfo to null." into sc-qpr1-dev am: 84a7a431cc am: ae1afdd8eb

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15935219

Change-Id: I3db5fcda91462084fd846f3f3d3937d309b3fc8f