Remove RelayoutBlock from WindowDecoration

We previously added the relayout block due to flashes that were caused
when onTaskInfo ran relayout between a transition. This occured because
we were setting task position and cropping the window in relayout. Now
that we are no longer setting the position/ window crop in relayout, we
no longer need the block.

Bug: 274674365
Test: Testing transitions manually to make sure there is no flash
Change-Id: Ic28cdb90b9def39acc8da57561eb6bed737d6b9e