Fix screenshot UI for insets

Previously, the screenshot UI was shown on top of display cutouts.
We want the animation (e.g. flash) to display over any insets, but
the screenshot preview and actions should respect insets. This
change makes the static UI respect insets, and sets the animation
so that it smoothly animates to the location of the static preview.

Bug: 153404471
Bug: 155272789
Fix: 153404471
Fix: 155272789
Test: manual -- tested full, partial, and from overview, with various
display cutouts on and off and with navbar set to gestural/2/3-button
mode.

Change-Id: I85100a674e1736dd6c198ee85fa07cd700e839b4