Add missing newline in lifetime macros.

PiperOrigin-RevId: 457410430
diff --git a/lifetime_annotations/lifetime_annotations_test.cc b/lifetime_annotations/lifetime_annotations_test.cc
index f6dccd9..5d31876 100644
--- a/lifetime_annotations/lifetime_annotations_test.cc
+++ b/lifetime_annotations/lifetime_annotations_test.cc
@@ -63,7 +63,7 @@
   for (char l = 'a'; l <= 'z'; ++l) {
     absl::StrAppendFormat(&result, "#define $%c $(%c)\n", l, l);
   }
-  absl::StrAppend(&result, "#define $static $(static)");
+  absl::StrAppend(&result, "#define $static $(static)\n");
   absl::StrAppend(&result, code);
   return result;
 }