Upgrade libprotobuf-mutator to dbe588bfb6922060e557fe5b8ee27d2923000c1a am: 2fcbc34326 am: 9ee6084729 am: 237cd6833b

Original change: https://android-review.googlesource.com/c/platform/external/libprotobuf-mutator/+/2262286

Change-Id: I1d1e3425231501133f3b8d9837488d6c2529af50
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>