Reland "Snap to relative position to snappd task when dismissing"

This reland commit ba61b98fca3a95f02b8802c4508fca5aa6903213 accidentally reverted by http://ag/15162411

Bug: 188793333
Test: manual
Change-Id: Iae07a67d528aa80e8f87d37758244d0c46b61cf7
2 files changed