build(deps): Bump firebase_core from 3.0.0 to 3.3.0 in /example

Bumps [firebase_core](https://github.com/firebase/flutterfire/tree/master/packages/firebase_core) from 3.0.0 to 3.3.0.
- [Release notes](https://github.com/firebase/flutterfire/releases)
- [Commits](https://github.com/firebase/flutterfire/commits/firebase_core-v3.3.0/packages/firebase_core)

---
updated-dependencies:
- dependency-name: firebase_core
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

example/pubspec.lock

@@ -92,26 +92,26 @@ packages:
     dependency: "direct main"
     description:
       name: firebase_core
-      sha256: "0d436d29b16fd9844a098ece2a3ce75efc290e5fe0844d282c5e8987173b0d02"
+      sha256: "3187f4f8e49968573fd7403011dca67ba95aae419bc0d8131500fae160d94f92"
       url: "https://pub.dev"
     source: hosted
-    version: "3.0.0"
+    version: "3.3.0"
   firebase_core_platform_interface:
     dependency: transitive
     description:
       name: firebase_core_platform_interface
-      sha256: c437ae5d17e6b5cc7981cf6fd458a5db4d12979905f9aafd1fea930428a9fe63
+      sha256: "3c3a1e92d6f4916c32deea79c4a7587aa0e9dbbe5889c7a16afcf005a485ee02"
       url: "https://pub.dev"
     source: hosted
-    version: "5.0.0"
+    version: "5.2.0"
   firebase_core_web:
     dependency: transitive
     description:
       name: firebase_core_web
-      sha256: "22fcb352744908224fc7be3caae254836099786acfe5df6e9fe901e9c2575a41"
+      sha256: e8d1e22de72cb21cdcfc5eed7acddab3e99cd83f3b317f54f7a96c32f25fd11e
       url: "https://pub.dev"
     source: hosted
-    version: "2.17.1"
+    version: "2.17.4"
   firebase_storage:
     dependency: "direct main"
     description:

example/pubspec.yaml

@@ -10,7 +10,7 @@ dependencies:
 
   dynamic_cached_fonts:
     path: ../
-  firebase_core: ^3.0.0
+  firebase_core: ^3.3.0
   firebase_storage: ^12.0.0
   async: ^2.8.2