Telephony: Speaker proximity only while in call (2/3)

Gives the option to only enable the speaker proximity
        feature during incall (speaker won't turn on
        while the phone is ringing, but will turn on
        after you remove the phone from your face, only
        after the receiving party has answered the call).

PS: fix line length
Change-Id: Iab64f73ae45626f35ac8f1ce952b99e4b2d69a2c

Conflicts:
	res/values/cm_strings.xml
	res/xml/call_feature_setting.xml