Profile: Filter on NETWORK_STATE_CHANGED instead of SUPPLICANT_STATE_CHANGED

For more reliable network change detection use NETWORK_STATE_CHANGED
instead of SUPPLICANT_STATE_CHANGED

Only set profile when profile actually changed.
Use getWifiSsid instead of getSSID so we dont have to strip double
quotes ourselves, add null pointer exception check because function can
now be called when WiFi is off.

Change-Id: I2b4ea65fdb484edb39a14725c648d9ab0d5d36fb