Fix missing socket closure in LocalSocketTest

Noticed as a result of 90e66cce7870a4aaa36e6a03946993dd33be395d.
One of the AF_UNIX sockets being created in three tests was not
being closed (until GC/finalization). Because the name is now
used in multiple tests some of the tests would fail in the CTS
test runner ("Address already in use") if no GC had occurred.

Bug: 3106438
Change-Id: I7debe5ed26d9d09e71a3d8a1b5b7d85b13e6e069
1 file changed