Assignment: Improve submission statement to cover all possible settings, support for the app

This issue only needs to be tested in 1 device. Login in mobile master as student. Go to MM Dev Testing > Assignment > Online text with click to submit and multiple attempts Create a new attempt and save it. In the assign entry page, above of the submit button, check that you see the message: "This assignment is my own work, except where I have acknowledged the use of the works of other people." Now go to "Group online text assignment" in the same section. Create a new attempt and save it. In the assign entry page, above of the submit button, check that you see the message: "This submission is my own work as a group member, except where I have acknowledged the use of the works of other people." Now go to "Group online text assignment (one student submits all)" in the same section. Create a new attempt and save it. In the assign entry page, above of the submit button, check that you see the message: "This submission is the work of my group, except where we have acknowledged the use of the works of other people."