How to attach file to email in Ionic Framework Android?

I'm using Ionic Framework to build an iOS / Android app which writes sqlite data to a CSV file, then attaches that file to an Email and sends it. The following code works correctly on iOS (actual device iPhone 5).

I don't have an Android device, but in the Android emulator (nexus 5), the file sent never has a file attachment (despite the emulator showing that it does).

Is there a different way I should be writing this code?

I looked at the documentation here, but it does not clarify

https://github.com/katzer/cordova-plugin-email-composer#adding-attachments

      $cordovaFile.writeFile(cordova.file.dataDirectory,
                             "PatientEncounters.csv",
                             data.join("\n"),
                             true)
        .then(function (success) {
          $cordovaEmailComposer.isAvailable().then(function() {
            var emailOpts = {
              to: [email],
              attachments: ['' +
                            cordova.file.dataDirectory.replace('file://','') + "PatientEncounters.csv"],
              subject: 'Patient Encounters',
              body: 'A CSV containing Patient Encounters is attached',
              isHtml: false
            };

            $cordovaEmailComposer.open(emailOpts).then(null, function () {
              // user cancelled email
            });

            return;
          }, function (error) {
            return;
          });


        }, function () {
          // not available
        });