Stubs generation should not depend on core_platform

Test: m droid
Change-Id: Ia3835306970445b6f224b1c329dc4e63b845e544
diff --git a/JavaLibrary.bp b/JavaLibrary.bp
index 75eee87..b85a861 100644
--- a/JavaLibrary.bp
+++ b/JavaLibrary.bp
@@ -672,7 +672,7 @@
     srcs: [":core_api_files"],
     java_version: "1.9",
     installable: false,
-    sdk_version: "core_platform",
+    sdk_version: "none",
     args: " --exclude-annotations " +
         "--hide-annotation libcore.api.Hide",
     merge_inclusion_annotations_dirs: ["ojluni-annotated-mmodule-stubs"],
@@ -731,7 +731,7 @@
     name: "core-current-stubs-nullability-validation",
     srcs: [":core_api_files"],
     installable: false,
-    sdk_version: "core_platform",
+    sdk_version: "none",
     annotations_enabled: true,
     args: "--hide-annotation libcore.api.Hide " +
         "--validate-nullability-from-merged-stubs ",