podman: [2.0 regression] Rootless non-root user capability are no longer added

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description

Capabilities set using --cap-add are no longer added to non-root user.

Steps to reproduce the issue:

1. podman run --user 1000 --device /dev/net/tun --cap-add NET_ADMIN fedora getpcaps 1

Describe the results you received:

Capabilities for `1’: =

Describe the results you expected:

Capabilities for `1’: = cap_net_admin+eip

Additional information you deem important (e.g. issue happens only occasionally):

This got introduced by fe69aa9ba385f5d44b95f549b6b223589131c1f7