Allow activity coalescing when starting from last launched uid

When task bounds do not match, activity coalescing was not allowed.
This was initially implemented in commit abf63715 to prevent
coalescing when a host application launches multiple activities
of different apps simultaneously. This change prioritizes the
UID check before the bounds check.

Bug: 430687520
Test: start an app to Desktop, to background, start it again to bubble
Flag: EXEMPT bugfix

Change-Id: Idfbdacf51afb79e9611797a04a64e974de35caed