Bump firebase-messaging from 23.0.5 to 23.0.6

Bumps firebase-messaging from 23.0.5 to 23.0.6.

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

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

app/build.gradle

@@ -347,7 +347,7 @@ dependencies {
     implementation "com.github.stateless4j:stateless4j:2.6.0"
 
     // upon each update first test: new registration, receive push
-    gplayImplementation "com.google.firebase:firebase-messaging:23.0.5"
+    gplayImplementation "com.google.firebase:firebase-messaging:23.0.6"
 }
 
 configurations.all {