Add Firefox versions for RTCDataChannel API (#13092)
Add Firefox versions for RTCDataChannel API (#13092)

This PR adds real values for Firefox and Firefox Android for the `RTCDataChannel` API.  The data was copied from their corresponding event handlers, which matches the versions when the interface was added (or in the case of `bufferedamountlow_event`, when the related features were added).
chrisdavidmills/browser-compat-data,mdn/browser-compat-data,chrisdavidmills/browser-compat-data,mdn/browser-compat-data