title: Start Perview failed camera in react native
body: <p>I have a component that it scans a QR code.this is my code:</p>
  
  <pre><code>import QRCodeScanner from 'react-native-qrcode-scanner';
  .
  .
  .
  &lt;QRCodeScanner
  cameraType={'front'}
  onRead={this.onSuccess.bind(this)} /&gt;
  .
  .
  .
  onSuccess(e) {
  console.warn(e.data);
  }
  </code></pre>
  
  <p>this is my plist and androidmanifest.xml:</p>
  
  <pre><code>&lt;key&gt;NSCameraUsageDescription&lt;/key&gt;
  &lt;string&gt;Your message to user when the camera is accessed for the first                     
  time&lt;/string&gt;
  &lt;key&gt;NSPhotoLibraryUsageDescription&lt;/key&gt;
  &lt;string&gt;Your message to user when the photo library is accessed for the    
  first time&lt;/string&gt;
  &lt;key&gt;NSMicrophoneUsageDescription&lt;/key&gt;
  &lt;string&gt;Your message to user when the microsphone is accessed for the 
  first time&lt;/string&gt;
  </code></pre>
  
  <p>androidmanifest.xml:</p>
  
  <pre><code>    &lt;uses-permission android:name="android.permission.INTERNET" /&gt;
      &lt;uses-permission android:name="android.permission.SYSTEM_ALERT_WINDOW" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" /&gt;
      &lt;uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" /&gt;
      &lt;uses-permission android:name="android.permission.READ_PHONE_STATE" /&gt;
      &lt;uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /&gt;
      &lt;uses-permission android:name="android.permission.READ_CONTACTS"/&gt;
      &lt;uses-permission android:name="android.permission.WRITE_CONTACTS"/&gt;
      &lt;uses-permission android:name="android.permission.VIBRATE"/&gt;
  
   &lt;uses-permission android:name="android.permission.CAMERA" /&gt;   &lt;uses-sdk
          android:minSdkVersion="16"
          android:targetSdkVersion="26" /&gt;
  
  &lt;/manifest&gt;
  </code></pre>
  
  <p>but I receive this error: Start Preview failed camera</p>
  
  <p>How can I resolve that?</p>
  
  <p>Thanks, advance</p>