title: can not find flutter android version code
body: <p>I was able to build the release version of my app and uploaded to play store, Now I want to update it and I need to change the <code>versionCode</code>. However when I look in my <code>&lt;android/app/build.gradle&gt;</code> the part which says version which is supposed to be an integer is now something like <code>flutterVersionCode.toInteger()</code> and <code>versionName</code> <code>flutterVersionName</code> is a bit confusing for me and I dont know where to change it from.</p>
  
  <pre><code>def localProperties = new Properties()
  def localPropertiesFile = rootProject.file('local.properties')
  if (localPropertiesFile.exists()) {
      localPropertiesFile.withReader('UTF-8') { reader -&gt;
          localProperties.load(reader)
      }
  }
  
  def flutterRoot = localProperties.getProperty('flutter.sdk')
  if (flutterRoot == null) {
      throw new GradleException("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
  }
  
  def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
  if (flutterVersionCode == null) {
      throw new GradleException("versionCode not found. Define flutter.versionCode in the local.properties file.")
  }
  
  def flutterVersionName = localProperties.getProperty('flutter.versionName')
  if (flutterVersionName == null) {
      throw new GradleException("versionName not found. Define flutter.versionName in the local.properties file.")
  }
  
  apply plugin: 'com.android.application'
  apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
  
  def keystoreProperties = new Properties()
  def keystorePropertiesFile = rootProject.file('key.properties')
  if (keystorePropertiesFile.exists()) {
      keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
  }
  
  android {
      compileSdkVersion 28
  
      lintOptions {
          disable 'InvalidPackage'
      }
  
      defaultConfig {
          // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
          applicationId "com.example.someApp"
          minSdkVersion 16
          targetSdkVersion 28
          versionCode flutterVersionCode.toInteger()
          versionName flutterVersionName
          testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
          multiDexEnabled true
      }
  
  signingConfigs {
      release {
          keyAlias keystoreProperties['keyAlias']
          keyPassword keystoreProperties['keyPassword']
          storeFile file(keystoreProperties['storeFile'])
          storePassword keystoreProperties['storePassword']
      }
  }
  buildTypes {
      release {
          signingConfig signingConfigs.release
          minifyEnabled true
          useProguard true
  
          proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'        
      }
  }
  }
  
  flutter {
      source '../..'
  }
  
  dependencies {
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'androidx.test:runner:1.1.1'
      androidTestImplementation 'androidx.test.espresso:espresso-core:3.1.1'
      //implementation 'com.google.firebase:firebase-core:15.0.2'
      //compile 'com.google.firebase:firebase-core:16.0.0'
      implementation 'com.google.firebase:firebase-core:15.0.2'
  
  }
  
  apply plugin: 'com.google.gms.google-services'
  </code></pre>