instead of fabricating a `/etc/password` manually, we can just
leave it to podman to add an entry in `/etc/password` in container.
as podman allows us to map user's account to the same UID in the
container. see
https://docs.podman.io/en/stable/markdown/options/userns.container.html.
this is not only a cosmetic change, it also avoid the permission denied
failure when accessing `/etc/passwd` in the container when selinux is
enabled. without this change, we would otherwise need to either add the
selinux lable to the bind volume with ':Z' option address the failure
like:
```
type=AVC msg=audit(1693449115.261:2599): avc: denied { open } for pid=2298247 comm="bash" path="/etc/passwd" dev="tmpfs" ino=5931 scontext=system_u:system_r:container_t:s0:c252,c259 tcontext=unconfined_u:object_r:user_tmp_t:s0 tclass=file permissive=0
type=AVC msg=audit(1693449115.263:2600): avc: denied { open } for pid=2298249 comm="id" path="/etc/passwd" dev="tmpfs" ino=5931 scontext=system_u:system_r:container_t:s0:c252,c259 tcontext=unconfined_u:object_r:user_tmp_t:s0 tclass=file permissive=0
```
found in `/var/log/audit/audit.log`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closes#15230
34e3302c01