Ignore OverlayHandlerView as active child

Summary:
On foldable devices, there's an issue whereas the topmost root view is of type `OverlayHandlerView`.

This doesn't seem to be related in any way to the running app's UI. Or at least is not something of interest when debugging the running app's UI (for example, ig4a).

This change effectively ignores the `OverlayHandlerView` instance as active child and instead returns the next to last root view.

Reviewed By: LukeDefeo

Differential Revision: D44579223

fbshipit-source-id: cea52289c5ba1e6a96817232ac54725b8d2f48d9

android/src/main/java/com/facebook/flipper/plugins/uidebugger/descriptors/ApplicationRefDescriptor.kt

@@ -18,7 +18,15 @@ object ApplicationRefDescriptor : ChainedDescriptor<ApplicationRef>() {
 
   override fun onGetActiveChild(node: ApplicationRef): Any? {
     val children = onGetChildren(node)
-    return if (children.isNotEmpty()) children.last() else null
+    if (children.isNotEmpty()) {
+      val last = children.last()
+      if (last.javaClass.simpleName.contains("OverlayHandlerView")) {
+        return children.getOrNull(children.size - 2)
+      }
+      return last
+    }
+
+    return null
   }
 
   override fun onGetBounds(node: ApplicationRef): Bounds = DisplayMetrics.getDisplayBounds()