Merge "Prevent swipe-to-dismiss conversation header" into rvc-dev am:...

Merge "Prevent swipe-to-dismiss conversation header" into rvc-dev am: e91a027e am: 891fba38 am: bacf3a26

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/11820083

Change-Id: I30b2e626f57405d0c60351149110e69cb22eafde