Add missing extensions, fix scan of bad media files.

Update extensions list in StagefrightMediaScanner.
Mark files that fail to scan as non-media files.

Bug: 31900187
Bug: 32045229
Bug: 77656952
Bug: 78682917
Change-Id: I78f21b044f3a038d6e78dbe9f461f650650afe8b
(cherry picked from commit 9abe5ee5)