title: Keystore Not Found for Signing Config 'release'
body: <p>I'm having a problem while running this command on Flutter: <code>flutter build appbundle --target-platform android-arm,android-arm64,android-x64</code> which I need to run in order to execute <code>flutter build apk</code>.</p>
  
  <p>build.gradle</p>
  
  <pre><code>def keystoreProperties = new Properties()
  def keystorePropertiesFile = rootProject.file('key.properties')
  if (keystorePropertiesFile.exists()) {
      keystoreProperties.load(new FileInputStream(keystorePropertiesFile))
  }
  
  signingConfigs {
         release {
             keyAlias keystoreProperties['keyAlias']
             keyPassword keystoreProperties['keyPassword']
             storeFile keystoreProperties['storeFile'] ? file(keystoreProperties['storeFile']) : null
             storePassword keystoreProperties['storePassword']
         }
      }
  
      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.release
          }
      }
  </code></pre>
  
  <p>key.properties</p>
  
  <pre><code>storePassword=XXXX
  keyPassword=XXXX
  keyAlias=key
  storeFile="C:/Users/User/Key/key.jks"
  
  </code></pre>
  
  <p>Error:</p>
  
  <pre><code>* What went wrong:
  Execution failed for task ':app:validateSigningRelease'.
  &gt; Keystore file 'D:\Projects\Flutter\iusefully\android\app\"C:\Users\User\Key\key.jks"' not found for signing config 'release'.
  </code></pre>