Only trigger (un)lock icon on longpress

Add a custom touch handler to the lock/unlock
icon affordance so it only triggers on long press.
It will no longer trigger on tap nor fling.

Fixes: 208431845
Fixes: 207551612
Test: manual, atest SystemUITests
Change-Id: I0b2561db55cc35a06a9981cdeb2e70922101c96c
Merged-In: I0b2561db55cc35a06a9981cdeb2e70922101c96c