Fix for data and roaming icons

- Enable data connected flag based on the data state.

- Do not display data icon in data connected state
if radio type is unknown

- Display data icon independent of voice service state
i.e even if voice network is unavailable

- Show cdma roaming indicators if either voice
or data is roaming.

- Cleanup roaming indicator default values.
Set default CDMA Eri index to roaming off

- Show service if either voice/data is in
service if ro.config.combined_signal is true

- Consider eri only when in service

- Add in service check to isCdmaEri.
roaming related information
in registration state will not be valid
during out of service.

Change-Id: I915421a6f5906d80ed5b8dd9c433115ad5df1f14
CRs-Fixed: 285986, 303275, 326204, 326634, 333008, 339297
(cherry picked from commit 5e973bedadf36b08a1e2a82745d912fcfdebb020)
(cherry picked from commit fd4dcb2c518eef3e655136cbd69c94b5a3fffb1b)
(cherry picked from commit c5b8a284415d65bad41915b3e50fed853d5f5110)
Verify apnContext is not null before it gets dereferenced

If this is still null a NPE will be thrown when it is dereferenced later on

Change-Id: I71ec478eb32425ca4242ee1eb366756648935350