Fix Aapt so that duplicate package ID errors are not incorrectly reported.

Aapt falsely reports package ID conflicts unless base packages are included
in strictly ascending order based on their package IDs. This fix addresses
that issue while still detecting and reporting conflicts correctly when they
actually exist.

Change-Id: Ic8059b87f919641d086df88d1556f5fa0063739f
WallpaperManager: add NULL pointer check for getCropAndSetWallpaperIntent

Originally the api 'getCropAndSetWallpaperIntent' does not check
whether the parsed parameter is a NULL pointer, as leads to the
whole app crash if it call this api with a null parameter accidentally.
A null pointer check logic is added into its original parameter check
logic, so that this API will throw an IllegalArgumentException if it
is parsed with a null pointer

Change-Id: Ib7de40e571419d09e1a744edc969eb7162766b75