Add icon to show which elements in ax tree are talkback-focusable

Summary: Puts an accessibility icon next to any elements in the ax tree that may be focused on when talkback is running to show that they are "accessibility-focusable". When any sidebar values are changed, the icon will show up/disappear accordingly.

Reviewed By: danielbuechele

Differential Revision: D9171781

fbshipit-source-id: f3b42624988aaef22040ac3325d745a12f0622db

src/ui/components/elements-inspector/elements.js

@@ -331,6 +331,8 @@ class ElementsRow extends PureComponent<ElementsRowProps, ElementsRowState> {
           return <DecorationImage src="icons/componentkit-logo.png" />;
         case 'componentscript':
           return <DecorationImage src="icons/componentscript-logo.png" />;
+        case 'accessibility':
+          return <DecorationImage src="icons/accessibility.png" />;
         default:
           return null;
       }