startCallTracking method
Starts tracking latency for a new call.
callId The unique identifier for the call.
isOutbound True for outbound calls, false for inbound.
Implementation
void startCallTracking(String callId, {bool isOutbound = false}) {
_callTrackers[callId] = _CallTrackingState(
startTime: DateTime.now().millisecondsSinceEpoch,
isOutbound: isOutbound,
);
markCallMilestone(callId, milestoneCallInitiated);
}