chore: Update preference screen title casing

[ILoveOpenSourceApplications]

Changes done according to #122 (comment).

[inotia00]

@KobeW50 How to change the format of the title in PreferenceScreen?

On YouTube, it is expressed as: Alternative tumbnails, Account menu

On YouTube Music, it is expressed as: Action Bar, Flyout Menu, Navigation Bar

It seems better to follow one of the two formats.

[KobeW50]

The native settings menus in YouTube and YT Music are sentence-cased (ex: Data saving)

RVX menu titles should follow the same format. Only the first word should be capitalized except when it's a proper noun.

I mean @KobeW50, did suggest the current PR change (see the PR description) , which I'm doing now for consistency across both the apps.

Oops this is entirely my fault. I misused the term "title-cased". I am sorry for your trouble.

I meant that "Flyout Menu" and "Action Bar" should be changed to "Flyout menu" and "Action bar"

I'll make the changes in a few hours when I'm on my laptop so that you don't work twice as much due to my mistake.

[inotia00]

Also, we use "Experimental Flags" instead of "Experimental flags". That should be changed as well, right?

Yeah, Experimental flags seems more appropriate.

[inotia00]

Thanks!