Gallery2: Can set picture as screen color background.

The upgrade of android4.4 make the set wallPaper activity
be executed when set picture as background color.

Add a condition to judge fromScreenColor and when judge the
fromScreenColor is set as true, then execute the activity
of set picture as color background activity instead of set
wallpaper activity.

CRs-Fixed: 623268

Change-Id: Id4dfa745f9d8379af084b8e2752f775ad85c9c52
Merge "Gallery2: Can set picture as screen color background." into du44