Enable "Protect sheets and ranges" option with Dropbox-integrated .gsheet

The option to protect sheets/ranges is available by default in Google Sheets normally, but for some reason, is lost when integrated with Dropbox. 

The ability to protect/lock previous entries is essential to ensure we keep accurate records that are not mistakenly over-written over time - we need data entered at the completion of a study to be immutable, and only allow new rows to be entered. While this exists in a Google Sheet outside of Dropbox, integration with Dropbox would make the .gsheet easier to access and located in a common repository with all of our other raw data/files.