ngCordova fileWrite() on Android Simulator - Error Code:10

Here is my code which keeps throwing Error Code 10-

if (ionic.Platform.isAndroid()){
$cordovaFile.writeFile(cordova.file.dataDirectory, ‘testdb.txt’,‘Hello World’, true).then(function (success) {
alert('success droid ’ + JSON.stringify(success));

      $cordovaFile.readFile(cordova.file.dataDirectory,'testdb.txt').then(function(s2){
        alert('s2 ' + JSON.stringify(s2));
      },function(err2){
        alert('err2 droid ' + JSON.stringify(err2));
      })

    }, function (error) {
      alert('error droid' + JSON.stringify(error));
    });
  }

Can anybody help me in identifying what is wrong with it?

Similar code for iOS works though!