Fix FD leak in ConnectivityManager.getConnectionOwnerUid

Add unit tests to verify that bug has been fixed.

Re-enable testGetConnectionOwnerUid() unit tests in presubmit. These
were disabled due to test flakiness caused by expected failures passing
as a result of other sockets on the system. This is fixed by checking
that failures do not have the UID of the calling process instead of
INVALID_UID since previously some Qualcomm telephony sockets were
causing lookup successes.

Test: atest InetDiagSocketTest#testGetConnectionOwnerUid
Test: ls -1 /proc/<pid of system_server>/fd | wca
Test: atest --generate-new-metrics 200 InetDiagSocketTest#testGetConnectionOwnerUid
   To verify flakes have been cleaned up.
Bug: 141603906
Bug: 141459241
Change-Id: Ib76674f10e4bd24952c557bac7b9c65fba42fdb2