[Bug] Audio balance shifts when changing volume via keyboard

[iamkartiknayak]

Issue/Description:
When adjusting the volume using the keyboard, the audio balance shifts:

• Decreasing volume when balance is in left, moves the balance to further left otherwise right (if on right side)
• Increasing volume when in right, moves the balance to further left otherwise right (if on left side)
• Once the balance reaches the center, it remains there and does not change further

This issue does not occur when changing the volume via the UI using cursor

Version:

cosmic-settings:
  Installed: 0.1.0~1743626025~24.04~d27ee21

Steps to Reproduce:

1. Put the balance to the center of left
2. Increase/Decrease the volume to see the shift to right & left respectively
3. Put the balance to the center of right
4. Increase/Decrease the volume to see the shift to left & right respectively
5. Notice that once it reaches center, it no longer changes

Expected Behavior:
The audio balance should remain unchanged when adjusting volume via the keyboard.

Other Notes:

• This issue occurs only when using the keyboard for volume control.

[iamkartiknayak]

The behavior of the thumb on balance slider has been changed since

Now the thumb moves to the center of the balance as soon as volume is being manipulated via keyboard.