Action chips in share sheet. (DO NOT MERGE)

Move the Copy button to a new row of chips below the
(now larger) preview. Optionally, if a proximity-sharing
service is installed, show that chip as well.

Bug: 143229724
Fixes: 144290152
Test: atest SystemUITests frameworks/base/core/tests/coretests
Change-Id: I0d6457df85bc937f72ca97da6b4b84b634a90daf