Animate in screenshot actions.

Switch container insets to padding instead of margin, allow drawing
outside.

Translate up the actions container during the screenshot UI entrance.

Bug: 329659738
Test: Manual inspection with slowed-down animations
Flag: ACONFIG com.android.sysui.screenshot_shelf_ui2 TRUNKFOOD
Change-Id: I96ef8a57b917be9635a059415898c9f56d3f436c