ColorResource should be platform-dependend

[Alex009]

now ColorResource is just sealed class with color constants. but we should use on each platform resources of platform. so we generate colors.xml on android, and should have some actual ColorResource(R.color.mycolor) on android. now we got:

actual object colors : ResourceContainer<ColorResource> {
  actual val valueColor: ColorResource.Single = Single(color = Color(0xB02743FF))

that not use platform resources at all...

[Alex009]

will be released in 0.21.0