Make XmpMotionPhotoDescriptionParser public

To be used by MediaProvider.

Bug: 205139624
Change-Id: Ibc8aa62eb5fc07e64692cc97e8191ec534be4770
Merged-In: Ibc8aa62eb5fc07e64692cc97e8191ec534be4770
Test: N/A
(cherry picked from commit 0a1d1bf619ec98e9fc0c073903a3763aebe0f0a9)
1 file changed