Add volume name while creating files in public volume

Previously, files created in public volume were added to database with
volume name as VOLUME_EXTERNAL_PRIMARY. Changed insertFileForFuse to
extract volume name from path when inserting a file using RELATIVE_PATH
and DISPLAY_NAME.

Test: atest packages/providers/MediaProvider
Bug: 150366834
Change-Id: Ibd7a64de4f35b6e2b8a4690fdfcf7cd7d3d1ed49
1 file changed