Adds Define Constraints for the editor assembly files (#391)

* Adds Define Constraints for the editor assembly files

* sets overrideReferences back to default false

---------

Co-authored-by: Vicky Clark <[email protected]>

Author: lee-aandrew

package/com.unity.formats.usd/Samples/ExportMesh/Editor/Unity.Formats.USD.ExportMesh.Editor.asmdef

@@ -1,5 +1,6 @@
 {
     "name": "Unity.Formats.USD.ExportMesh.Editor",
+    "rootNamespace": "",
     "references": [
         "Unity.Formats.USD.ExportMesh"
     ],
@@ -11,7 +12,9 @@
     "overrideReferences": false,
     "precompiledReferences": [],
     "autoReferenced": true,
-    "defineConstraints": [],
+    "defineConstraints": [
+        "UNITY_INCLUDE_TESTS"
+    ],
     "versionDefines": [],
     "noEngineReferences": false
 }

package/com.unity.formats.usd/Samples/ImportMesh/Editor/Unity.Formats.USD.ImportMeshEditor.asmdef

@@ -1,5 +1,6 @@
 {
     "name": "Unity.Formats.USD.ImportMeshEditor",
+    "rootNamespace": "",
     "references": [
         "Unity.Formats.USD.ImportMesh",
         "Unity.Formats.USD.Runtime",
@@ -13,7 +14,9 @@
     "overrideReferences": false,
     "precompiledReferences": [],
     "autoReferenced": true,
-    "defineConstraints": [],
+    "defineConstraints": [
+        "UNITY_INCLUDE_TESTS"
+    ],
     "versionDefines": [],
     "noEngineReferences": false
 }