SVT-AV1/README.libaom: set 'Shipped in Chromium: no'

This code was disabled in
crrev.com/211ec3973ed8617391e046140d1c70f097860e10.

Bug: 446258249
Change-Id: I3c298530377de632af553984b050fdb076308bad

third_party/SVT-AV1/README.libaom

diff --git a/third_party/SVT-AV1/README.libaom b/third_party/SVT-AV1/README.libaom
index 334ce51..bf6e287 100644
--- a/third_party/SVT-AV1/README.libaom
+++ b/third_party/SVT-AV1/README.libaom
@@ -4,7 +4,7 @@
 Version: 8ff99c90359330d2e807757c9425560bbc452ff3
 License: BSD-3-Clause-Clear
 License File: LICENSE.md
-Shipped in Chromium: yes
+Shipped in Chromium: no
 Security Critical: yes
 
 Description: