Change comment on Yoga measure modes in RN (#41732)

Summary:
Pull Request resolved: #41732

Was reading the code in this file and noticed that this comment is no longer true after D51068417 (facebook/yoga#1460). Updated the comment to reflect the current state of things

Changelog: [Internal]

Reviewed By: NickGerleman

Differential Revision: D51730986

fbshipit-source-id: beaa5de9576d86e56def35f6e970376c7be8f7ee

packages/react-native/ReactCommon/react/renderer/components/view/YogaLayoutableShadowNode.cpp

@@ -604,13 +604,11 @@ void YogaLayoutableShadowNode::layoutTree(
   react_native_assert(!std::isinf(minimumSize.width));
   react_native_assert(!std::isinf(minimumSize.height));
 
-  // Internally Yoga uses three different measurement modes controlling layout
-  // constraints: `Undefined`, `Exactly`, and `AtMost`. These modes are an
-  // implementation detail and are not defined in `CSS Flexible Box Layout
-  // Module`. Yoga C++ API (and `YGNodeCalculateLayout` function particularly)
-  // does not allow to specify the measure modes explicitly. Instead, it infers
-  // these from styles associated with the root node.
-  // To pass the actual layout constraints to Yoga we represent them as
+  // Yoga C++ API (and `YGNodeCalculateLayout` function particularly)
+  // does not allow to specify sizing modes (see
+  // https://www.w3.org/TR/css-sizing-3/#auto-box-sizes) explicitly. Instead, it
+  // infers these from styles associated with the root node. To pass the actual
+  // layout constraints to Yoga we represent them as
   // `(min/max)(Height/Width)` style properties. Also, we pass `ownerWidth` &
   // `ownerHeight` to allow proper calculation of relative (e.g. specified in
   // percents) style values.