Merge "libc++fs is part of libc++ now." into main am: 8392c707 am: d901f1e2

Original change: https://android-review.googlesource.com/c/platform/frameworks/base/+/3126193



Change-Id: I4e7a9d17460851b6008651edee11560d3c6b0932
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>