Move SymbolGenerator from BazelStarlarkContext to StarlarkThread.

PiperOrigin-RevId: 624032725
Change-Id: Id93c473752905c90b76282f39ce1fd9147887b1b
diff --git a/src/test/java/com/google/devtools/build/lib/packages/LicenseTest.java b/src/test/java/com/google/devtools/build/lib/packages/LicenseTest.java
index 5db294d..ee7f5f1 100644
--- a/src/test/java/com/google/devtools/build/lib/packages/LicenseTest.java
+++ b/src/test/java/com/google/devtools/build/lib/packages/LicenseTest.java
@@ -54,7 +54,7 @@
             input,
             FileOptions.DEFAULT,
             Module.create(),
-            new StarlarkThread(mutability, StarlarkSemantics.DEFAULT));
+            StarlarkThread.createTransient(mutability, StarlarkSemantics.DEFAULT));
     mutability.freeze();
     return Sequence.cast(parsedValue, String.class, "evalAsSequence() input");
   }