Announce for accessiblity when taskbar is invoked/closed

Test: Manual
Bug: 265620540
Change-Id: I6660be7716ec59c765f3d54f8fe9889eaaf56e10

src/com/android/launcher3/views/IconButtonView.java

@@ -29,6 +29,7 @@ import android.graphics.drawable.ColorDrawable;
 import android.graphics.drawable.Drawable;
 import android.os.Build;
 import android.util.AttributeSet;
+import android.view.accessibility.AccessibilityEvent;
 
 import androidx.annotation.ColorInt;
 import androidx.annotation.NonNull;
@@ -78,6 +79,12 @@ public class IconButtonView extends BubbleTextView {
         }
     }
 
+    @Override
+    public void onPopulateAccessibilityEvent(AccessibilityEvent event) {
+        super.onPopulateAccessibilityEvent(event);
+        event.getText().add(this.getContentDescription());
+    }
+
     /** Sets given Drawable as icon */
     public void setIconDrawable(@NonNull Drawable drawable) {
         ColorStateList tintList = getBackgroundTintList();