Revert "Old derp"

This reverts commit 73b4dc1b6be0feb6587f1b336994fd008028288a.
EthernetDataTracker: Set network available on connected

This change fixes state mismatch found in the bugs below,
and makes the code look consistent with disconnect().

In startMonitoring(), reconnect() is called before mNMService.registerObserver().
Then dhcpThread.run() could finish without getting interfaceLinkStateChanged() callback.
In such a case, mNetworkInfo has connected but not-available state - which is contradictory.

Bug: 8113933, 8291000, 8291039
Change-Id: I29d74f8d09dcffb97d6c9f8198811bca046fef0c