Extended Usage of isIndexedDBAvailable to Service Worker (#3585)

* extended usage of isIndexedDBAvailable to service worker

* Create silly-moles-rush.md

* Update silly-moles-rush.md

Author: XuechunHou

.changeset/silly-moles-rush.md

@@ -0,0 +1,6 @@
+---
+"firebase": patch
+"@firebase/util": patch
+---
+
+Extended Usage of `isIndexedDBAvailable` to Service Worker

packages/util/src/environment.ts

@@ -136,14 +136,11 @@ export function isSafari(): boolean {
 }
 
 /**
- * This method checks if indexedDB is supported by current browser
- * @return true if indexedDB is supported by current browser
+ * This method checks if indexedDB is supported by current browser/service worker context
+ * @return true if indexedDB is supported by current browser/service worker context
  */
 export function isIndexedDBAvailable(): boolean {
-  if (!('indexedDB' in window) || indexedDB === null) {
-    return false;
-  }
-  return true;
+  return 'indexedDB' in self && indexedDB !== null;
 }
 
 /**