Merge "libc++fs is part of libc++ now." into main am: 546e89303a am: a98e75e97e

Original change: https://android-review.googlesource.com/c/platform/system/extras/+/3113999

Change-Id: I0a46952469ae5ea40f614fbe54662d706a6c6088
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>