DeskClock: Fix flicker and blackscreen issue.

(1) When enter the deskclock at first time, and can see + in actionBar
in short time. this is a flicker issue.

(2) Change the items in SettingsActivity and then exit, you can see flick
or blackscreen in short time.

Change-Id: Id02318cd9562367bf8b5daec4d54b3a7bb6bca21
CRs-Fixed: 1032811
2 files changed