Merge "Sharesheet: remove 2 separators, restyle the 3rd." into sc-dev am: 832779a5 am: 7bed52f4 am: a5345812

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/15377016

Change-Id: I3b0c3e675a12f32ba92c21ddc5a9bfb7650127bd