Revert removing FLAG_ACTIVITY_CLEAR_TOP from intent
Removing that flag from the intent provokes some apps not being able to finish pressing the back key.
This change doesn't affect other opened apps.

Change-Id: I81a47f8e648114d8e2144a3b9854ede299d67871
HALO: keep apps in recents

Change-Id: I9ede8a1aba8d6721f077a39a31b6cc5cd8272dc2

Conflicts:
	services/java/com/android/server/am/ActivityRecord.java