Log UsbConnectorStateChanged events

The following would the logged:
1. Status of the connection - connected/disconnected.
2. Port id as a device could have multiple ports.

Bug: 118783261
Test: Manually tested by running: adb shell cmd stats print-logs,
adb logcat | grep statsd | grep \(70\)
Change-Id: Ideea36c7745293f5b6ec9cc35fd5f709f5175d5a