Fabric: Exposing `multiline` as a prop in ViewManager's generated ViewConfig

Summary:
We need to expose the `multiline` prop in View Manager class to enable Fabric component to use it.

Changelog: [Internal] Fabric-specific internal change.

Reviewed By: sammy-SC

Differential Revision: D18950429

fbshipit-source-id: 69b225b24b4512a1ea21381daacbf868a23ccf6d

Libraries/Text/TextInput/RCTBaseTextInputViewManager.m

@@ -69,6 +69,11 @@ RCT_EXPORT_SHADOW_PROPERTY(text, NSString)
 RCT_EXPORT_SHADOW_PROPERTY(placeholder, NSString)
 RCT_EXPORT_SHADOW_PROPERTY(onContentSizeChange, RCTBubblingEventBlock)
 
+RCT_CUSTOM_VIEW_PROPERTY(multiline, BOOL, UIView)
+{
+  // No op.
+  // This View Manager doesn't use this prop but it must be exposed here via ViewConfig to enable Fabric component use it.
+}
 
 - (RCTShadowView *)shadowView
 {