Updating hashbrown crate am: 18967b9e40

Original change: https://android-review.googlesource.com/c/platform/external/rust/crates/hashbrown/+/2163166

Change-Id: I4fc0072999e92cb7d537988106c03a12c4a2f4c1
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>