NetworkController: Fix hiding signal strength icon when no SIM icon shown

* This now handles the case where the no SIM icon is overlaid with the
* signal strength icon when WiFi is disabled or not connected.

Change-Id: Ie5bf3d9f5cb4752ff631c8fcf7b1a5628219b31b
TD_SCDMA signal strength support

Change-Id: I0a86eba7c51834054400233044610fa08e7f7fcd