Attributes Metadata

Summary:
Before this change, attributes and attribute metadata were intermingled and sent as one unit via subtree update event.

This represented a few issues:
- Repetitiveness. For each declared and dynamic attribute, metadata was included on each value unit.
- Metadata can vary in size and thus can have a negative impact on payload size.
- The attribute name which is part of metadata is a string which always overhead on processing.
- Metadata instantiation is not cheap thus this also incurs in processing overhead i.e. even instantiating a single string can have an impact.

The proposal is to separate metadata of attributes from the actual node reported attributes. This solves the problems mentioned above.

Reviewed By: LukeDefeo

Differential Revision: D40674156

fbshipit-source-id: 0788551849fbce53065f819ba503e7e4afc03cc0

android/src/test/java/com/facebook/flipper/plugins/uidebugger/EnumMappingTest.kt

@@ -39,9 +39,7 @@ class EnumMappingTest {
   @Test
   fun testTurnsIntoEnumInspectable() {
     assertThat(
-        visibility.toInspectable(View.GONE, true),
-        equalTo(
-            InspectableValue.Enum(
-                Enumeration(setOf("VISIBLE", "INVISIBLE", "GONE"), "GONE"), mutable = true)))
+        visibility.toInspectable(View.GONE),
+        equalTo(InspectableValue.Enum(Enumeration(setOf("VISIBLE", "INVISIBLE", "GONE"), "GONE"))))
   }
 }