Make useMediaQuery return the correct value on the first render

[alshakero]

Hi!

This is a small patch for #21676.

Description

Instead of defaulting to false for useMediaQuery's hook state, I made it default to the actual value and thus returning the right value from the very beginning.

How has this been tested?

I also added a test for this case that doesn't call act, so it doesn't wait for the effects to take place but still expects the right value.

Types of changes

This is a non-breaking change. And doesn't change the hook's API at all. At least not the expected API.

Checklist:

• My code is unit tested. But not manually tested because I couldn't find any usage of the hook within Gutenberg.
• My code follows the WordPress code style.
• My code follows the accessibility standards.
• My code has proper inline documentation.
• I've included developer documentation if appropriate.
• I've updated all React Native files affected by any refactorings/renamings in this PR.

[youknowriad]

Looks and works great, Thanks for the fix