CHROMIUM: portage: Allow FEATURES=fakeroot when root

When running inside a user namespace we have UID 0, but we can't
actually write files with arbitrary UIDs, so we still need to use
fakeroot.

BUG=b:262460834
TEST=tar tvf ../bazel-bin/external/_main~portage~portage/internal/packages/stage1/target/board/chromiumos/net-dialup/ppp/ppp-2.4.9-r6.tbz2 ./etc

Change-Id: Ib7b1138a3e56b27aa0294821222f333ae8a13110
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/portage_tool/+/4519681
Reviewed-by: Shuhei Takahashi <nya@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Tested-by: Raul Rangel <rrangel@chromium.org>
Commit-Queue: Raul Rangel <rrangel@chromium.org>
1 file changed