Send USER_PRESENT broadcast after keyguard animation finishes

This fixes a potential race between receiving USER_PRESENT
broadcast and testing if keyguard is finished
(KeyguardManager.isKeyguardLocked())

This also fixes an issue where USER_PRESENT isn't sent when
device encryption is enabled.

Fixes bug 17322844
Fixes bug 17301385

Change-Id: Icab3068c24032942ffdf6554d6d53cc656ae6666