Update ShannonIms CERTIFICATE to PRESIGNED for Lynx am: 8b07e4935a

Original change: https://googleplex-android-review.googlesource.com/c/device/google/lynx/+/25398343

Change-Id: Ib0da96dcf1915466a5d4a96b8a98185d361e99f3
Signed-off-by: Automerger Merge Worker <[email protected]>