Extending DNS event reporting

This adds hostname, array of addresses, total count of IP addresses
and uid to the existing pipeline.
Currently ignores the new data it receives, further work will be
done in the subsequent CLs.

Test: for now just the benchmarking, in the future unit and CTS

Bug: 29748723
Change-Id: Ice7db208282934e74f0e1808ffbae96d476c4216
(cherry picked from commit 14c9d2d0)