SystemUI: Allow showing data type with roaming indicator on MSIM.

  If a device sets a system property "ro.config.always_show_roaming"
  the roaming indicator will not replace the data type icon, but create
  a new indicator alongside signaling that the sim is roaming.

Change-Id: I60ac97572b9b50e4809dbd809a8e5a2d0763542e
SystemUI: Fix signal cluster hiding data icon on data disabled.

 972a6e652 removed the zero'ing of the datatype icon, restore the
 original behavior.

Change-Id: I5794582673b13835d9264d7615d640308bf3fbe3
Merge remote-tracking branch 'cyanogenmod/cm-11.0'