log connectivity state change

log when networks become available and lost, for all transport types
In statsd, we can use net id to uniquely identify a network. We should
be able to count connectivity state changes similar to what BatteryStats
does.

Bug: 115561340
Test: cts test
Change-Id: Ieac4d243e27d5d368a77e5607dec51964912240d
1 file changed
tree: 0ba01c98e95558f0deb3c5adf763645a25cfb534
  1. stats/