fix: Fix memory leak on SimpleAbrManager (shaka-project#5478)

closes
[shaka-project#5477](shaka-project#5477)

Moving `this.onNetworkInformationChange_ = null;` before creating the
navigator.connection event listener.
Currently it resets it to null after creating the listener so the
release() wont be able to remove the eventlistener

lib/abr/simple_abr_manager.js

@@ -48,6 +48,9 @@ shaka.abr.SimpleAbrManager = class {
     /** @private {shaka.abr.EwmaBandwidthEstimator} */
     this.bandwidthEstimator_ = new shaka.abr.EwmaBandwidthEstimator();
 
+    /** @private {?function():void} */
+    this.onNetworkInformationChange_ = null;
+
     // Some browsers implement the Network Information API, which allows
     // retrieving information about a user's network connection. We listen
     // to the change event to be able to make quick changes in case the type
@@ -98,9 +101,6 @@ shaka.abr.SimpleAbrManager = class {
     /** @private {ResizeObserver} */
     this.resizeObserver_ = null;
 
-    /** @private {?function():void} */
-    this.onNetworkInformationChange_ = null;
-
     /** @private {shaka.util.Timer} */
     this.resizeObserverTimer_ = new shaka.util.Timer(() => {
       if (this.config_.restrictToElementSize) {