BootAnimation: Fix boot animation with hidden cutout

We do this by storing the masking inset in a persistent property.
The boot animation then animates itself to where it would be if that
masking inset were applied, then changes the viewport.

For this to work, we also need to make sure the DisplayManagerService
has the right overlay right at the start.

Bug: 112876936
Test: Hide cutout, then reboot. Verify boot animation is smooth.
Change-Id: I3e988b2340b2e0d2be3939bdc6878704c234ccc8