Make Markup fade in from screenshots

Uses RemoteAnimationAdapter to override the pending app transition
so that Markup fades in in-place instead of doing a slide
translation from the bottom. This is a workaround for b/190806800.

Bug: 188696811
Fix: 188696811
Test: manual (visual inspection)
Change-Id: I0838bb5dc1cd271456779cecb9a7710d7a3ad7a1