Remove unused feature flag: useMapNativeAccessor

Summary:
useMapNativeAccessor isn't being used anywhere.

Changelog: [Internal] Removing unused internal feature flags: mUseMapNativeAccessor and mUseArrayNativeAccessor

Reviewed By: mdvacca

Differential Revision: D20788147

fbshipit-source-id: bf670508326813602cb544f86d3d2164651d3394

ReactAndroid/src/main/java/com/facebook/react/config/ReactFeatureFlags.java

@@ -19,12 +19,6 @@ public class ReactFeatureFlags {
   /** Whether we should load a specific view manager immediately or when it is accessed by JS */
   public static boolean lazilyLoadViewManagers = false;
 
-  /** Reduce the number of Java-JS interops while accessing native arrays */
-  public static boolean useArrayNativeAccessor = false;
-
-  /** Reduce the number of Java-JS interops while accessing native maps */
-  public static boolean useMapNativeAccessor = false;
-
   /**
    * Should this application use TurboModules? If yes, then any module that inherits {@link
    * com.facebook.react.turbomodule.core.interfaces.TurboModule} will NOT be passed in to C++