convert addEventHandler to arrow function

Author: jaissica12

src/events.interfaces.ts

@@ -51,6 +51,7 @@ export interface IEvents {
     ): void;
     logEvent(event: BaseEvent, eventOptions?: SDKEventOptions): void;
     logImpressionEvent(
+        // https://go/j/SDKE-1199
         impression: SDKImpression | SDKImpression[] | SDKProductImpression | SDKProductImpression[],
         attrs?: SDKEventAttrs,
         customFlags?: SDKEventCustomFlags,

src/events.ts

@@ -406,13 +406,13 @@ export default function Events(
         }
     };
 
-    this.addEventHandler = function(
+    this.addEventHandler = (
         domEvent: string,
         selector: string | Node,
         eventName: ((element: HTMLLinkElement | HTMLFormElement) => string) | string,
         data: ((element: HTMLLinkElement | HTMLFormElement) => SDKEventAttrs) | SDKEventAttrs,
         eventType: valueof<typeof EventType>
-    ): void {
+    ): void => {
         let elements: ArrayLike<Element> | Element[] = [];
         let element: DOMHandlerElement;
         let elementIndex: number;