Don't panic if no certificates found am: b7550aa0 am: 3495c736 am: e3082c62

Original change: https://android-review.googlesource.com/c/platform/build/soong/+/2596605



Change-Id: Ib12a76a2742d27ceacd311725f888688f707a1a9
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>