Upgrade google-benchmark to v1.8.4 am: 4643d20873 am: b1b10179d4

Original change: https://android-review.googlesource.com/c/platform/external/google-benchmark/+/3118328

Change-Id: I5a3432f991f12f44ae728b8ef4af37a1722df306
Signed-off-by: Automerger Merge Worker <[email protected]>