Remove ThemedTextView and set the text color based on background color luma

[EmmanuelMess]

  /**
   * Correctly sets text color based on a given background color so that the
   * user can see the text correctly
   */
  @JvmStatic
  fun setIntelligentTextColor(context: Context, textView: TextView, backgroundColor: Int) {
    val red = Color.red(backgroundColor) * 0.299f
    val green = Color.green(backgroundColor) * 0.587f
    val blue = Color.blue(backgroundColor) * 0.114f

    val luma = (red + green + blue) / 255.0f

    val color = if(luma > 0.5) android.R.color.black else android.R.color.white

    textView.setTextColor(Utils.getColor(context, color))
  }