Update kernel to builds 7855344 am: 9ad3d4fe22 am: 8437727078 am: 72a7aa44f7

Original change: https://googleplex-android-review.googlesource.com/c/device/google/cuttlefish_prebuilts/+/16128402

Change-Id: Ic0347377afad81b2f31786f8ea8a40dfeb0a6f7c