init method
Initializes the Signed Call SDK
initProperties - configuration for initialization
initHandler - to get the initialization update(i.e. success/failure)
Implementation
@override
Future<void> init(
Map<String, dynamic> initProperties, SignedCallInitHandler initHandler) {
_initHandler = initHandler;
return _methodChannel
.invokeMethod(SCMethodCall.init, {argInitProperties: initProperties});
}