Add a method to get `BuildConfigurationKey` from `ActionLookupKey`.

PiperOrigin-RevId: 406831509
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionValue.java b/src/main/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionValue.java
index 48dba2a..514236a 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionValue.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/ActionTemplateExpansionValue.java
@@ -65,6 +65,11 @@
       return actionLookupKey.getLabel();
     }
 
+    @Override
+    public BuildConfigurationKey getConfigurationKey() {
+      return actionLookupKey.getConfigurationKey();
+    }
+
     public ActionLookupKey getActionLookupKey() {
       return actionLookupKey;
     }