Query libnetd_client for the appropriate netId for host resolution.

If libnetd_client can't be found, operate as before and use the default netId
potentially overriden by a more specific netId passed in to
android_get*fornet().

(cherry picked from commit 559c7842)

Change-Id: I42ef3293172651870fb46d2de22464c4f03e8e0b