Exit Recents with HOME instead of WCT when locked

We need to merge the next incoming transition (KEYGUARD_UNOCCLUDING) to
get a smooth transition. Sending a WCT at the end makes merging the
two transitions together difficult because the WCT is missing and may
even generate a third transition afterwards if the end result doesn't
match.

Bug: 293862576
Change-Id: Ifd19f0d445ffe21f3bb068882321a55091377173