Fix DatagramChannelTest failures

Fix for recvfrom returning 0 after orderly shutdown didn't
take into account that sender can send empty datagram.
Added a check if the sockaddr struct is invalid before
returning when recvfrom returns 0.

Bug: 28054926
Change-Id: I4bf24407999165b86a2ef2758ded3ca82d3eb575
(cherry picked from commit 1cf88e0b56b32a7932b9d35d6f1b811bffb882d1)
1 file changed