KernelUtils.h - add describeArch() am: 47ddbe066c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/libs/net/+/23391172

Change-Id: Ie4b209b1b46278bb616e18cb7ff79f897745944f
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>