Upload files using a CompositeUploadFileJob making the upload cancelable
Summary
Use a CompositeUploadFileJob to upload multiple files sequentially using 1 notification.
Test Plan
Apply patch and verify that:
- multiple files are send sequentially using 1 notification
- while an upload is running sharing additional files to the same device updates the running job
- a running upload job can be canceled by pressing the "Cancel" action button of the notification