Make the header INVISIBLE when alpha is 0

That way, clicks are not relayed to children.

Also, make the Reset menu item surface as action if it fits, for better
discoverability.

Test: manual
Test: atest LargeScreenShadeHeaderControllerTest
Fixes: 255708561
Change-Id: I853736f48ea97560f4b9ff438832d1372e0c59cc
(cherry picked from commit 6d4e7a81629afc17874c7e84e20f74c1470e2066)
(cherry picked from commit 1070f0f01184653a9247e3ba401aa5672c11ad84)
Merged-In: I853736f48ea97560f4b9ff438832d1372e0c59cc
4 files changed