fix(adjust): added missing AdjustConfig method (#3886)

src/@awesome-cordova-plugins/plugins/adjust/index.ts

@@ -240,6 +240,10 @@ export class AdjustConfig {
   private hasDeferredDeeplinkCallbackListener() {
     return this.deferredDeeplinkCallback !== null;
   }
+
+  private hasConversionValueUpdatedCallbackListener() {
+    return this.conversionValueUpdatedCallback !== null;
+  }
 }
 
 export class AdjustAppStoreSubscription {
@@ -766,4 +770,4 @@ export class Adjust extends AwesomeCordovaNativePlugin {
   getAppTrackingAuthorizationStatus(): Promise<number> {
     return;
   }
-}
+}