Correct grammatical error in the JavaDoc of the Application interface

[SonicGDX]

Corrects "this facilities" to "these facilities" in Application.java

[Frosty-J]

I approve of minor fixes.

This paragraph I'm not too fond of anyway. When it says you can query the operating system, I expect to be able to check if we're on Windows, macOS, Solaris. But getType() isn't that granular and UiUtils is required instead.