> All previews are generated on demand when the corresponding
header expands
> Using ItemAnimator to animate layout changes when preview loads
Bug: 196238313
Test: Manual
Change-Id: I0cb859c8443c2c536399e4063f58baecfc7416ad
Linking header position to an empty entry in the recyclerView,
instead of calculating the vertical scroll position. This
allows the header to be in sync with the recyclerView scroll and
item animations
Other simplifications:
> Moving top collapse handle out of header view (it doesn't scroll)
> Removing background clipping logic from full-sheet
> Moving tab bar inside the header view
Bug: 196464142
Test: Verified on device
Change-Id: Iae5a0ae9af7ce258e1b391b8e85c5c270fe56197
Sunny Goyal