Add back phone notification LED settings backend.

Change-Id: I1f6834872ac8320e43a0c5d77b1dc8d3654fa99b
Telephony: Dismissable voicemail notifications

Ported from cm-10.2:
http://review.cyanogenmod.org/#/c/35023

Change-Id: Iccd01210cdd9a43167392fc09debbfc4cb23b6f6
[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

Change-Id: I6e801bda2ab447ab6cf8418220d6854e257f7d9e
Mobile Network Battery Saver Mode

When idle (screen off) switching to 2G can help extend
battery life as 2G generally uses less power than 3G or LTE.

    + 30 seconds after screen turns off, set network type to 2G
    + If a music player is active (playing), do not set network to 2G
    + When device is unlocked, reset to orignial network type

Settings -> More -> Mobile Networks -> Battery saving mode
needed for increasing ring feature