Update aria-invalid based on valid length

src/Umbraco.Web.UI.Client/src/views/propertyeditors/textarea/textarea.html

@@ -9,7 +9,8 @@
             ng-keyup="change()"
             ng-trim="false"
             ng-required="model.validation.mandatory"
-            aria-required="{{model.validation.mandatory}}">
+            aria-required="{{model.validation.mandatory}}"
+            aria-invalid="{{validLength ? false : true}}">
         </textarea>
 
         <span ng-messages="textareaFieldForm.textarea.$error" show-validation-on-submit >

src/Umbraco.Web.UI.Client/src/views/propertyeditors/textbox/textbox.html

@@ -8,7 +8,7 @@
                val-server="value"
                ng-required="model.validation.mandatory"
                aria-required="{{model.validation.mandatory}}"
-               aria-invalid="False"
+               aria-invalid="{{validLength ? false : true}}"
                ng-trim="false"
                ng-change="change()" />