Bump com.google.firebase:firebase-messaging from 23.3.1 to 23.4.0

Bumps [com.google.firebase:firebase-messaging](https://github.com/firebase/firebase-android-sdk) from 23.3.1 to 23.4.0.
- [Changelog](https://github.com/firebase/firebase-android-sdk/blob/master/docs/make_release_notes.py)
- [Commits](https://github.com/firebase/firebase-android-sdk/commits)

---
updated-dependencies:
- dependency-name: com.google.firebase:firebase-messaging
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

app/build.gradle

@@ -60,7 +60,7 @@ dependencies {
     implementation "androidx.multidex:multidex:$multidex_version"
     implementation 'com.firebaseui:firebase-ui-auth:8.0.2'
     implementation 'com.google.firebase:firebase-auth:22.3.0'
-    implementation 'com.google.firebase:firebase-messaging:23.3.1'
+    implementation 'com.google.firebase:firebase-messaging:23.4.0'
     implementation 'com.google.firebase:firebase-database:20.3.0'
     implementation 'com.google.firebase:firebase-storage:20.3.0'
     implementation 'com.google.firebase:firebase-firestore:24.9.1'