chore(crashlytics): update AGP for example app (#17064)

Author: russellwheatley

packages/firebase_crashlytics/firebase_crashlytics/example/android/settings.gradle

@@ -18,7 +18,7 @@ pluginManagement {
 
 plugins {
     id "dev.flutter.flutter-plugin-loader" version "1.0.0"
-    id "com.android.application" version "7.3.0" apply false
+    id "com.android.application" version "8.1.0" apply false
     // START: FlutterFire Configuration
     id "com.google.gms.google-services" version "4.3.15" apply false
     id "com.google.firebase.crashlytics" version "2.8.1" apply false