ssci: update autoroll exemption for NotoSansCJK

Change-Id: I831747de3ae9a6cfe16603f3d1c9f09314f58ac6
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/135810
Auto-Submit: Jiewei Qian <qjw@google.com>
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/third_party/NotoSansCJK/README.pdfium b/third_party/NotoSansCJK/README.pdfium
index b9ccd37..485545d 100644
--- a/third_party/NotoSansCJK/README.pdfium
+++ b/third_party/NotoSansCJK/README.pdfium
@@ -4,6 +4,7 @@
 Revision: cf29231ab8029678af4bbc1a9480e2b296a5b2d3
 License: OFL-1.1
 License File: LICENSE
+Update Mechanism: Static (https://crbug.com/422921492)
 Security Critical: no
 Shipped: no