Summary:
Layer selection is pretty easy to miss, as reported in for example: https://fb.workplace.com/groups/flippersupport/permalink/1098169193997071/
Moved the layer selection to the top of the view and gave it some highlighting + dynamic height. The section is no longer collapsible.
Changelog: [Layout] Make the layer selection more prominent
Reviewed By: priteshrnandgaonkar
Differential Revision: D27708650
fbshipit-source-id: c86a55c3a20794aee86e64b6766b2ca4dd6b563f
0fe879c838