Add material you color theming

[Brokoli5191]

If you have noticed or not WhatsApp has only material you design not material you theming so that WhatsApp takes the color from your wallpaper. Would be really cool if you could implement that. Then are all my apps following material you theming because the green WhatsApp is looking very inappropriate to my blue colour theme. Btw very cool project, its propably one of the First Open source WhatsApp mods. I appreciate you work