Fix NullpointerException in MediaMetadataRetriever

According to the API documentation and the ICS implementation
the setDataSource(String) method throws an
IllegalArgumentException if path is null. In JB a
NullpointerException is thrown instead. This fix restores
the earlier behaviour.

Change-Id: Ic47baadf91076acc227d92d84f6b8d1d6ecd0c03
base: fix constant conflict

There is a conflict 2 media type which shares the same constants which is a DVIX and JPEG.
which causes some app to think jpeg is a dvix video file
It was due to the merge of the qualcomm patches (patch: http://review.cyanogenmod.org/#/c/28960/ ) which was merged on the 23rd

Change-Id: Ida014adab4a954aa81a16d1ff401f9847f87d1a5