SystemUI: Add ethernet network icon

Add an ethernet network icon to the statusbar network area.

Change-Id: I019740f360b5f9cc85f404f75d38e38896182a81

Conflicts:
	packages/SystemUI/src/com/android/systemui/statusbar/SignalClusterView.java
	packages/SystemUI/src/com/android/systemui/statusbar/policy/NetworkController.java