Catch RuntimeException when opening 3gp files for inspection.

When reading metadata from .3gp files, FileManager can crash if the file
is unreadable. MediaMetaDataRetriever.setDataSource() throws
RuntimeException if this happens. Catch it.

Fixes NIGHTLIES-958.

Change-Id: I465f7c961793b468e0469a5844894f3ed56b374c
(cherry picked from commit 4bd0d070)
(cherry picked from commit 839ffc36)
(cherry picked from commit ad9e5195)