Remove FLAG_ACTIVITY_NEW_TASk when there is transition

Making activities launch in a separate task breaks the page transition.
Reviewed the history of the addition of these flags, they seem stale and
are no longer needed, so remove these when the transition is applied.

Bug: 189412031
Test: Tap on any badged entry and see it being launched in the same
task.

Change-Id: I60b2ec0b2772cd3bdc8c4ebbc83cedd2a603492a