Check cell radio flag before enabling APM

When airplane mode is enabled all radios listed
in AIRPLANE_MODE_RADIOS are toggled off.
Check global settings for the cell radio tristate
values on, off and off-due-to-airplane-mode.

b/26896610

Change-Id: I9400c66d4a58f2c71e5359874d70fda921e8542d
1 file changed