Use mobile as the default rendering method on mobile when Vulkan is supported

[clayjohn]

This fixes an oversight from #65541. When I renamed the project settings I forget to set the default mobile renderer to the mobile renderer. This resulted in an unexpected performance decrease for mobile users as they are suddenly using the clustered renderer without warning.

[akien-mga]

You forgot the docs ;)

[akien-mga]

It's worth noting that this probably won't work for the Android editor and Web editor due to this: #64100

But I think I'll fix #64100 eventually even if reduz believes overrides shouldn't be applied in the editor, I think we have enough proof that they're needed.

[akien-mga]

Thanks!