Open all files with O_NOFOLLOW.

SD cards don't support symlinks, so we have no reason to try
following them if somehow an evil caller is able to sneak them into
the database.

Bug: 124329382
Bug: 200682135
Test: atest --test-mapping packages/providers/MediaProvider
Change-Id: Idb1f3ee1db90913a97a50515003f211519037066
Merged-In: Idb1f3ee1db90913a97a50515003f211519037066
1 file changed