This reverts commit 1a7e67190228a8ff3b92e7e5496a8db8ff306cca.
Bring back the changes from Stan Chesnutt regarding link-status-change
notifications. The comment from the original patch was:
Propagate new link-status-change message to any NetworkManagementService
observers. Also fix the syntax of the "interface-status-change" message. Add
a null handler in the ThrottleService and Tethering classes (plus fix names).
Change-Id: I42cbed692024de32275cad234f42ff23ab7e9d8d
Signed-off-by: Mike J. Chen <mjchen@google.com>