title: When building my flutter app, it fails with GradleExeption
body: <p>When I try to build my app for public release I get this error from the app level <code>build.gradle</code>. I'm getting the error below:</p>
  
  <pre><code>Launching lib\main.dart on SM G973F in debug mode...
  Initializing gradle...
  Resolving dependencies...
  * Error running Gradle:
  ProcessException: Process "C:\Users\tbsvst18tedbom\AndroidStudioProjects\tab_truth_true\android\gradlew.bat" exited abnormally:
  
  FAILURE: Build failed with an exception.
  
  * Where:
  Build file 'C:\Users\tbsvst18tedbom\AndroidStudioProjects\tab_truth_true\android\app\build.gradle' line: 11
  
  * What went wrong:
  Could not compile build file 'C:\Users\tbsvst18tedbom\AndroidStudioProjects\tab_truth_true\android\app\build.gradle'.
  &gt; startup failed:
    build file 'C:\Users\tbsvst18tedbom\AndroidStudioProjects\tab_truth_true\android\app\build.gradle': 11: unable to resolve class GradleExeption 
     @ line 11, column 11.
           throw new GradleExeption("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
                 ^
  
    1 error
  
  
  * Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.
  
  * Get more help at https://help.gradle.org
  
  BUILD FAILED in 1s
    Command: C:\Users\tbsvst18tedbom\AndroidStudioProjects\tab_truth_true\android\gradlew.bat app:properties
  
  Finished with error: Please review your Gradle project setup in the android/ folder.
  </code></pre>
  
  <p>This is the app level <code>build.gradle</code> code:</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 GradleExeption("Flutter SDK not found. Define location with flutter.sdk in the local.properties file.")
  }
  
  def flutterVersionCode = localProperties.getProperty('flutter.versionCode')
  if (flutterVersionCode == null) {
      flutterVersionCode = '1.0.0'
  }
  
  def flutterVersionName = localProperties.getProperty('flutter.versionName')
  if (flutterVersionName == null) {
      flutterVersionName = '1.0'
  }
  
  apply plugin: 'com.android.application'
  apply plugin: 'kotlin-android'
  apply from: "$flutterRoot/packages/flutter_tools/gradle/flutter.gradle"
  
  android {
      compileSdkVersion 29
  
      sourceSets {
          main.java.srcDirs += 'src/main/kotlin'
      }
  
      lintOptions {
          disable 'InvalidPackage'
      }
  
      defaultConfig {
          // TODO: Specify your own unique Application ID (https://developer.android.com/studio/build/application-id.html).
          applicationId "com.tab.tab_truth_true"
          minSdkVersion 21
          targetSdkVersion 29
          versionCode flutterVersionCode.toInteger()
          versionName flutterVersionName
          testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
          multiDexEnabled true
      }
  
      buildTypes {
          release {
              // TODO: Add your own signing config for the release build.
              // Signing with the debug keys for now, so `flutter run --release` works.
              signingConfig signingConfigs.debug
          }
      }
  }
  
  flutter {
      source '../..'
  }
  
  dependencies {
      implementation "org.jetbrains.kotlin:kotlin-stdlib-jdk7:$kotlin_version"
      testImplementation 'junit:junit:4.12'
      androidTestImplementation 'com.android.support.test:runner:1.0.2'
      androidTestImplementation 'com.android.support.test.espresso:espresso-core:3.0.2'
      implementation 'com.google.firebase:firebase-ads:18.3.0'
  }
  
  apply plugin: 'com.google.gms.google-services'  // Google Play services Gradle plugin
  </code></pre>
  
  <p>I have tried everything, what I know, but achieved nothing.  please help me out.</p>