"vh" unit is not available in the unit control when added in theme.json

[carolinan]

Description

When support for custom units is enabled in theme.json using this format:

{
	"version": 1,
	"settings": {
		"spacing": {
			"customPadding": true,
			"units": [ "px", "em", "rem", "vh", "vw" ]
		}
	}
}

then the vh is not available in the unit control in the editors.
The other units are available.

Step-by-step reproduction instructions

1. Add the code above to a theme.json file in a theme.
2. In either editor, add a block that has support for custom padding like a group block or cover.
3. Select the padding control and see that vh is missing.

Expected behaviour

I expect the unit to be selectable.

Actual behaviour

It is not selectable.

---

vh in the unit control:
https://github.com/WordPress/gutenberg/blob/trunk/packages/components/src/unit-control/utils.js#L36

And vh support for cover block:
https://github.com/WordPress/gutenberg/blob/trunk/packages/block-library/src/cover/shared.js#L55

WordPress information

• WordPress version: 5.7.1
• Gutenberg version: trunk
• Are all plugins except Gutenberg deactivated? yes
• Are you using a default theme (e.g. Twenty Twenty-One)? TT1 Blocks

Device information

• Device: desktop
• Operating system: windows 10
• Browser: Chrome Version 90.0.4430.212

[aristath]

It looks like all CSS_UNITS values are currently hardcoded in all packages, investigating.