message: android/ios border styles
diff: .CustomSelect__container .FormField__border {
  border: solid 1px var(--field_border);
  - border-radius: 8px;
  }
  .CustomSelect__container .Select--mimicry:focus .FormField__border {
  border-color: var(--field_border);
  }
  -.CustomSelect__open .FormField__border {
  +.FormField--ios.CustomSelect__open .FormField__border {
  + border-radius: 10px 10px 0 0;
  +}
  +
  +.FormField--android.CustomSelect__open .FormField__border {
  border-radius: 8px 8px 0 0;
  }
  