Lockscreen : Ensure window bounds change after view animations

Changing window bounds when a view inside the window is performing
animations, causes flickers. Ensure we change window bounds
only after all the animations have completed.

Change-Id: I2143d3d15cdfe660d864e1af902267b0903b2afa
(cherry picked from commit cc008494)

CYNGNOS-2177

Change-Id: Ie5ca22f5d83bf80db3436c2a949e5225b9a71b3c