(Chore): Update example app's build.gradle file

Author: vickz84259

example/push_notifications/android/app/build.gradle

@@ -27,7 +27,7 @@ apply plugin: 'kotlin-android'
 apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
 
 android {
-    compileSdkVersion flutter.compileSdkVersion
+    compileSdkVersion 33
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -46,7 +46,7 @@ android {
         // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
         applicationId "com.talkjs.flutter_push_example"
         minSdkVersion 19
-        targetSdkVersion flutter.targetSdkVersion
+        targetSdkVersion 33
         versionCode flutterVersionCode.toInteger()
         versionName flutterVersionName
     }