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

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

Change-Id: Ifc407c51fa0837be1fe55311bf58f5d1e1a7c76b
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>