DO NOT MERGE Only send notification activity intents after dismissing Keyguard

Defers delivery of contentIntent and activity actions until
the lockscreen has been dismissed, so that activities don't
launch beneath it.

Bug: 14491010
Change-Id: Ic8c61c18a75d4f0da2d82a0a8a038a5d98ebb71f
(cherry picked from commit 79f640dd0d02c1cc199937b160d8f7abd3c1eaeb)