Add method to start transition on intent launch.

This forces the task to correctly start the TRANSIT_OPEN transiiton in
Desktop mode when launching an intent from the taskbar and prevent it
from opening in full screen.

Fixes: 361366053
Flag: EXEMPT bugfix
Test: manual test
Change-Id: I6ce85cdfdf2b027a57cbca8402baf2ed7421f3bb
3 files changed