Add T-Mobile US branded icons to custom

[hdoublearp]

I've added two branded T-Mobile US icons. The 5G icon is from the OnePlus 7T Pro 5G McLaren and is T-Mobile's original standalone 5G icon. The 5G UC icon was introduced with the iPhone 12/13 and Pixel 6 series.

[programminghoch10]

This could be license problematic, either we need a custom remake of those icons, or you need to find a license for it. If the icon is in a pixel device, it's likely it will also end up in AOSP. You can see that all AOSP icons and the codeaurora icons have their license included.