Delegate deletion of mediaprovider downloads to FileSystemProvider.

Using ContentResolver.delete() directly on MediaProvider doesn't work
for uris corresponding to directories. For now, delegate this
deletion to FileSystemProvider which will try deleting all entries
regex-matching the file path.

Bug: 135031305
Test: manual
Change-Id: Iac18d0fd0be05758aaf2c03971d716592d96699b
1 file changed