Merge "libc++fs is part of libc++ now." into main am: b6e21e8ebb am: 5d9bdaae0e

Original change: https://android-review.googlesource.com/c/platform/system/security/+/3126253

Change-Id: Id5a4b3d5649e9202854088a303de2e88c8973835
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>