fix(ui5-messagestrip): fix close button accessibility (#2352)

Author: fifoosid

packages/main/src/MessageStrip.hbs

@@ -1,12 +1,16 @@
 <div class="{{classes.root}}"
 	id="{{_id}}"
-	role="alert"
+	role="note"
 	dir="{{effectiveDir}}"
 	aria-live="assertive"
-	aria-labelledby="{{_id}}">
+	aria-labelledby="{{_id}}"
+>
 
 	{{#unless noIcon}}
-		<div class="ui5-messagestrip-icon-wrapper">
+		<div
+		class="ui5-messagestrip-icon-wrapper"
+		aria-hidden="true"
+		>
 			{{#if iconProvided}}
 				<slot name="icon"></slot>
 			{{else}}