Update ShannonIms CERTIFICATE to PRESIGNED for Lynx am: 8b07e4935a am: f587c06637

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

Change-Id: Ib2a9054996d06e8c3aa30a6f1b870716c99237e8
Signed-off-by: Automerger Merge Worker <[email protected]>