StatusBar: Add support for carrier customizaion by overlay

1. update arrays defined in arrays.xml, change their type to
   string-array, so that their items can be parsed correctly
   under run-time overlay.
2. update TelephonyIcons.java to get names of array items first
   and then get their reference ids.
3. Show separate no-sim icons for different slots.
4. Show data activity icons.
5. Show wifi activity icons.

CRs-Fixed: 627830
CRs-Fixed: 623278

Change-Id: I77ef4c9feeb194da0125cd11bf4abca3085e015e