Change: Stream handling and double-close in UploadFileFromContentUriWorker

Both the content resolver input stream and the file output stream from UploadFileFromContentUriWorker have been closed via use blocks, and the redundant double-close of the output stream has been removed.

https://github.com/owncloud/android/issues/4798
https://github.com/owncloud/android/pull/4799
