fix(alert): update styles for rtl (#17129)

- apply border correctly to 2 button mode in iOS
- radio: position icon correctly (fixes #16295)
- checkbox: position icon correctly
- remove scrollbar with radio/checkbox
- updates e2e test to include rtl

https://screenshot.ionicframework.com/5447404/d8bad6a

references #17012

core/src/themes/ionic.functions.string.scss

@@ -103,7 +103,8 @@
       $list: append($list, ":host(#{$addHostSelector}) #{$selector}", comma);
 
     } @else {
-      $list: append($list, "#{$addHostSelector} #{$selector}", comma);
+      // TODO host-context should be for scoped only
+      $list: append($list, ":host-context(#{$addHostSelector}) #{$selector}", comma);
     }
   }