[2/2] Telephony: allow disabling call end sound

Also remove the category around the intrusive
incall settings since more settings are added
below and this looks then strange

PS7
correct defaultValue

Change-Id: I37477582ecb3a8b74eb80db351401d83aab92b82

Conflicts:

	res/values/custom_strings.xml
Telephony: implement noise suppression for phone calls (2/2)

Forward port from cm-10.2

Change-Id: Ie72449f952f99b410fbb5bc4a8e6cbc833e6176f

Conflicts:

	res/values/mahdi_strings.xml