New brush export

Not necessary for the b/38321023 fix;
this is just to keep the descriptors in sync

Change-Id: I4e8ce15ecc2ebfe892075fb5ea533256459003a5

Author: dubois

UnitySDK/Assets/TiltBrush/Assets/Brushes/Basic/Hypercolor/Hypercolor.asset

@@ -17,7 +17,7 @@ MonoBehaviour:
   m_Material: {fileID: 2100000, guid: e8ef32b1baa8460a9c2c9cf8506794f5, type: 2}
   m_IsParticle: 0
   m_uv0Size: 3
-  m_uv0Semantic: 0
+  m_uv0Semantic: 3
   m_uv1Size: 0
   m_uv1Semantic: 0
   m_bUseNormals: 1