Update `ActionEnvironmentFunction.Key` to use `@AutoCodec.Interner` instead of `@AutoCodec.Instantiator`.

PiperOrigin-RevId: 602395504
Change-Id: Ie6f386f4cac1b2c44e83d437d24e73628d96c666
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ActionEnvironmentFunction.java b/src/main/java/com/google/devtools/build/lib/skyframe/ActionEnvironmentFunction.java
index 6e0f758..0ee0f67 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ActionEnvironmentFunction.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ActionEnvironmentFunction.java
@@ -61,12 +61,16 @@
       super(arg);
     }
 
-    @VisibleForSerialization
-    @AutoCodec.Instantiator
-    static Key create(String arg) {
+    private static Key create(String arg) {
       return interner.intern(new Key(arg));
     }
 
+    @VisibleForSerialization
+    @AutoCodec.Interner
+    static Key intern(Key key) {
+      return interner.intern(key);
+    }
+
     @Override
     public SkyFunctionName functionName() {
       return SkyFunctions.ACTION_ENVIRONMENT_VARIABLE;