Fix test for Guid to string change

com.unity.perception/Tests/Runtime/GroundTruthTests/KeyPointGroundTruthTests.cs

             const string label = "TestTemplate";
             var template = CreateTestTemplate(guid, label);
 
-            Assert.AreEqual(template.templateID, guid);
+            Assert.AreEqual(template.templateID, guid.ToString());
             Assert.AreEqual(template.templateName, label);
             Assert.IsNull(template.jointTexture);
             Assert.IsNull(template.skeletonTexture);