[3/3] services/Telephony: Add Network Tiles

      Add an LTE tile and a 2G/3G mobile network tile.

      The LTE tile requires that at least one (1) of the following configs
      be present in the device's build.prop in order to show:
          telephony.lteOnCdmaDevice=1
          telephony.lteOnGsmDevice=1

      The 2G/3G tile toggles between 3G Only, 2G Only and 2G/3G.

      If LTE is turned on the 2G/3G tile is disabled (shows unknown).
      The reverse is also true, turning on the 2G/3G tile disables LTE tile.

Linked commits:
      frameworks/base
      frameworks/opt/telephony