Feature/UI ds 453 improve close button aria labels on Alert (#454)

* Improves ARIA labels on Alert close button

* Updates snapshots

Author: tjbarber

spec/__snapshots__/Storyshots.test.js.snap

@@ -512,7 +512,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close success"
         className="close"
         onClick={[Function]}
         type="button"
@@ -641,7 +641,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close info"
         className="close"
         onClick={[Function]}
         type="button"
@@ -734,7 +734,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close announcement"
         className="close"
         onClick={[Function]}
         type="button"
@@ -827,7 +827,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close error"
         className="close"
         onClick={[Function]}
         type="button"
@@ -920,7 +920,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close warning"
         className="close"
         onClick={[Function]}
         type="button"
@@ -1052,7 +1052,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close announcement"
         className="close"
         onClick={[Function]}
         type="button"
@@ -1187,7 +1187,7 @@ exports[`Storyshots Design System/Alert With Call To Action 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close announcement"
         className="close"
         onClick={[Function]}
         type="button"
@@ -1316,7 +1316,7 @@ exports[`Storyshots Design System/Alert With Dismiss 1`] = `
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close success"
         className="close"
         onClick={[Function]}
         type="button"

src/Alert/Alert.jsx

@@ -107,7 +107,7 @@ function Alert(props) {
         props.onDismiss && (
           <div className="Alert__close">
             <button
-              aria-label="close"
+              aria-label={`close ${props.type}`}
               className="close"
               type="button"
               onClick={() => props.onDismiss(props.id)}

src/Toast/__snapshots__/withToast.test.jsx.snap

@@ -90,7 +90,7 @@ Array [
       className="Alert__close"
     >
       <button
-        aria-label="close"
+        aria-label="close success"
         className="close"
         onClick={[Function]}
         type="button"