Doc update re use of MATCH_UNINSTALLED flag

This change updates the docs for the MATCH_UNINSTALLED flag to note that
without the QUERY_ALL_PACKAGES permission, uninstalled packages will not
be returned.

Bug: 149846504
Test: builds
Change-Id: Id0c5b7f29172bd334dc1b2a32ce1f4eb7b1f0bd3
1 file changed