Fix layer.mask not being reset after recycle

Summary:
Changelog: [Internal]

If `layer.mask` was set and the view got reused without having a different `layer.mask`, this value would persist between reuses.

I also added a call to `super finalizeUpdates` as it is best practice to call super, the parent class right now doesn't do anything but in the future we might add there some default logic.

Reviewed By: shergin

Differential Revision: D20030174

fbshipit-source-id: c90be3f4e9a8f3814000f177a3d50061f5aa120c

React/Fabric/Mounting/ComponentViews/View/RCTViewComponentView.mm

@@ -267,6 +267,7 @@ using namespace facebook::react;
 
 - (void)finalizeUpdates:(RNComponentViewUpdateMask)updateMask
 {
+  [super finalizeUpdates:updateMask];
   if (!_needsInvalidateLayer) {
     return;
   }
@@ -399,6 +400,7 @@ static RCTBorderStyle RCTBorderStyleFromBorderStyle(BorderStyle borderStyle)
           colorComponentsFromColor(borderMetrics.borderColors.left).alpha == 0 || self.clipsToBounds);
 
   if (useCoreAnimationBorderRendering) {
+    layer.mask = nil;
     if (_borderLayer) {
       [_borderLayer removeFromSuperlayer];
       _borderLayer = nil;