Fix an incorrect comment in JavaLibrary.bp.

The procedure for updating the nullability warnings file changed
during the review of https://r.android.com/801554 but this comment was
not updated to reflect that.

Test: n/a (only affects comments)
Fixes: 142060419
Change-Id: Iaa603cad40a5aac91931662dcefb665a447bd836
diff --git a/JavaLibrary.bp b/JavaLibrary.bp
index 3022660..4d21721 100644
--- a/JavaLibrary.bp
+++ b/JavaLibrary.bp
@@ -833,8 +833,8 @@
 //   m art-module-public-api-stubs-nullability-validation
 // To check that there are only the expected nullability warnings:
 //   m art-module-public-api-stubs-nullability-validation-check-nullability-warnings
-// To update the the list of known expected nullability warnings:
-//   m art-module-public-api-stubs-nullability-validation-update-nullability-warnings
+// (If that check fails, it will provide instructions on how to proceed,
+// including the command to run to update the expected warnings file.)
 droidstubs {
     name: "art-module-public-api-stubs-nullability-validation",
     srcs: [":art_module_api_files"],