Only launch an activity in an existing task if activity types match

Activities with FLAG_ACTIVITY_NEW_TASK and FLAG_ACTIVITY_CLEAR_TASK
flags, when sharing the home activity's task, could cause the home
activity to be cleared. Later when home is launched again, a reset
of the task will be triggered each time.

Don't put an activity into a task unless the activity types match.
(This covers both home and recents activities.)

bug: 21880868
Change-Id: Ida26d187a6552914826bf45e537a731b3a15ea70