s4-common: HTCQualcommRIL: Recognize HTC radio state 13

Reference QualcommSharedRIL.java from cm-11.0 or elsewhere and you'll
find 'RIL_INT_RADIO_ON_HTC = 13'. This was previously added to RIL.java,
but it's obviously only pertinent to old HTC devices, so let's add it
here.

Change-Id: I0082175abbbb1f2bae23002dd48024697f60a593