Frameworks: use a layer drawable for the keyguard

in preperation to the new navbar and statusbar transparency
managment which will come it is more consistent on custom image
and color fill on lockcreen to use a layerdrawable to add the
shadow on top of the image to keep on transparency of the background
the shadow like it is suggested by google

Change-Id: I22df7652b8be42cab1c9d1f0a13797da40a75dd9
Hide new non-standard APIs and permission

These were breaking builds due to the public API modification

Change-Id: I603fcf0601f40fb315086859aa03ef5b7ec39248
Revert lockscreen code from previous commits.  Breaks things instead
of fixing them.  Wasnt a clean pick, so i will look at this later
to see what went wrong.

Change-Id: I0a0d3337a0126740e11dce8531ade586c04068ac
Signed-off-by: scott <scott@ubuntu.com>