Clamp volume to step size when incrementing/decrementing
This makes it so that the volume will snap to a multiple of the step size whenever it is incremented/decremented using hotkeys, scrolling on applet, etc.
We can expect that there are two major types of users when it comes to adjusting volume with up/down:
Users who tap up and down until they're happy with the volume, disregarding the UI indicators or the actual number of the volume. This patch doesn't affect them. Their muscle memory won't be affected; they'll still adjust the volume the same way.
Users who gague volume using the number displayed on the screen. This patch improves their user experience by making it easier for them to reason about the number displayed on the screen. It's easier (and more aesthetic) to count 25 -> 30 -> 35 or 15 -> 30 -> 45 instead of 13 -> 28 -> 43.