Media process is crashing with NullPointer exception

Sometime, while creating thumnails list of media files in
compose MMS->attach file,  filepath may be null due to
synchronization issue.
Adding NULL check to avoid NUllPointer exception.

Change-Id: Id6cf5612a959b3ae15b44bc60dbbcbe40c624f09
CRs-Fixed: 636494
wallpapercropper: OOM issue while opening *.bmp image

This change manages setting of large images as
wallpapers without encountering OOM.

CRs-fixed: 619815
Change-Id: I3a32ec4b42050b146076f0adf6b6e65afd6fae4e

Conflicts:
	packages/WallpaperCropper/src/com/android/wallpapercropper/WallpaperCropActivity.java
frameworks/base: Fix change propagating issue

destroyLayer() function has been modified in kk. It is not correct
to propagate the UI corruption fix from jb to kk without considering
the new changes made in kk. This change is to make it align with
the new code in kk.

Change-Id: I34d11b230b9390fe8a989ab6f9c7d3a48d586205