Add collapsable to RCTViewManager as property

Summary:
Changelog: [internal]

collapsable was not passed to Fabric because view configs are built using Paper' ViewManagers.

Reviewed By: p-sun

Differential Revision: D27944688

fbshipit-source-id: 73a5646e25b3dd7a1a9dfc1079406047ab483d88

React/Views/RCTViewManager.m

@@ -301,6 +301,13 @@ - (RCTShadowView *)shadowView
   }
 }
 
+RCT_CUSTOM_VIEW_PROPERTY(collapsable, BOOL, RCTView)
+{
+  // Property is only to be used in the new renderer.
+  // It is necessary to add it here, otherwise it gets
+  // filtered by view configs.
+}
+
 #define RCT_VIEW_BORDER_PROPERTY(SIDE)                                                               \
   RCT_CUSTOM_VIEW_PROPERTY(border##SIDE##Width, float, RCTView)                                      \
   {                                                                                                  \