RIL: fix signal for legacy gsm devices

our parcels are short causing mLteRssnr to be 0 which  is a valid
value and causes SignalStrength to think we are an LTE device.

implement as oldRil "signalstrengthgsm"

Change-Id: Id1b47dbee6cc875bc2cde2f499f6ba788fa9ccb5
Set audio mode after accepting the call

Set the audio mode to incall immediately after accepting the call and not wait
till call is reported as ACTIVE by RIL. This is done to speed up time taken for audio
to set up the voice path

(CM change: Remove calls to Rlog, since we haven't imported that yet)

Bug: 7612431
Change-Id: I8008edc64928016ab94aa6d770de248b5d85dc93
Merge remote-tracking branch 'github/jellybean' into aosp