Settings: Wifi extension feature.

    1 Add wifi ap priority setting UI
    2 Add autoconnect UI
    3 Add disconnect menu
    4 Add cell->wlan UI
    5 Add cell->wlan hint UI
    6 Add wlan->cell UI
    7 Add notify ap connected UI

CRs-Fixed: 952877
Change-Id: Id5855c6657115b45491ca789ec0ea3809d41ebe5