Merge "libc++fs is part of libc++ now." into main am: ef376ed30d

Original change: https://android-review.googlesource.com/c/platform/frameworks/av/+/3315774

Change-Id: Ie5b58437eaee66a607c8422c02bef438cb831898
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>