Letters activity: Accept and back options doesn't work in tablet mode

[DeepakMuddha]

In letters activity v24.1, the "Accept" and "Back" options doesn't work when used in tablet mode.
To reproduce:

1.Open the XO in tablet mode
2.Open Letters activity v24.1
3.Start the game and arrange some letters and now click on "Accept" or "Back" options

Result: Nothing happens when clicked on accept or back options. If you touch the screen after clicking on accept/back options then it responds and give the result.

Expected result: When clicked on Accept or Back options, then appropriate result should display for the user.

​https://sugardextrose.org/issues/3689