Merge "libc++fs is part of libc++ now." into main am: 5206ec3f08 am: 355cc6e87a

Original change: https://android-review.googlesource.com/c/platform/frameworks/native/+/3128500

Change-Id: I6196d8043d85381989bb3dc4f8afd8025ea5db1d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>