fix #650: Sound Volume Button works correctly now

[Mystic-Slice]

Description

Fix issue #650

Testing

• Step 1 Open game options from the Main Menu Screen
• Step 2 Try changing Sound Volume

Working video

https://user-images.githubusercontent.com/73862377/154787178-9a229865-920e-4903-bfac-c2bb9109d8a2.mp4

Pre Pull Request Checklist:

• [x] Code has been scanned with SonarLint
• [x] There are no errors present in the project
• [x] Code has been formatted and indented
• [x] Methods have appropriate Javadoc (How to write Javadoc)

[Mystic-Slice]

Thanks for fixing this!

By the way, I found another bug whilst testing this. If you change the sound settings in the in-game menu and then exit to the main menu, then the sound values in the main menu options will not have changed. I'd suggest setting the initial values in an overridden onAdded method.

Hey! Thnkx for the review! I have fixed the problem of the volume buttons not being in sync. Should work as expected now.

Note: I have not added the Map Pan Speed and Input Mode buttons in the onAdded method considering that these settings can be changed only in the Options screen and so will not cause any discrepancies