When ro.telephony.disable-call is set to true the phone disable actual calls. It provides a way to test in user-debug builds for stability runs. See bug 2031157.
modified: java/com/android/internal/telephony/TelephonyProperties.java
modified: java/com/android/internal/telephony/cdma/CdmaCallTracker.java
modified: java/com/android/internal/telephony/gsm/GsmCallTracker.java
modified: java/com/android/internal/telephony/TelephonyProperties.java
modified: java/com/android/internal/telephony/cdma/CdmaCallTracker.java
modified: java/com/android/internal/telephony/gsm/GsmCallTracker.java