Fix descriptor leak after accepting connections

After accepting a connection on a listening socket and
storing the resulting FileDescriptor into a newly created
LocalSocketImpl, the new impl's "descriptor was created
locally and should be closed normally" flag should be set.

Bug: 11805817

(cherry picked from commit 3e7305c6)

Change-Id: I723d7c5544ee4b6858894c215716cbc32a958df1