juju add-cloud fails with confined snap - creating ~/.local/share/juju

[Nobuto Murata]

How to reproduce:

1. Launch a LXD container with jammy on jammy

   lxc launch -e ubuntu:jammy juju-confined-snap-test
   lxc exec juju-confined-snap-test -- sudo -i -u ubuntu

2. install Juju inside the LXD container

   $ sudo snap install juju --channel 3.1

3. Configure a cloud

$ cat > clouds.yaml <<EOF
clouds:
  maas:
    type: maas
    auth-types: [oauth1]
    endpoint: http://192.168.151.1:5240/MAAS
EOF

$ juju add-cloud --client maas -f clouds.yaml

-> ERROR cannot load ssh client keys: mkdir /home/ubuntu/.local: permission denied

WORKAROUND:
execute the following before running `juju add-cloud`

$ mkdir -p ~/.local/share/juju/ssh/

Aug 04 01:44:16 t14 kernel: audit: type=1400 audit(1691081056.327:2305): apparmor="DENIED" operation="file_inherit" namespace="root//lxd-juju-confined-snap-test_<var-snap-lxd-common-lxd>" profile="snap-update-ns.juju" name="/dev/pts/2" pid=409297 comm="5" requested_mask="wr" denied_mask="wr" fsuid=1000000 ouid=1001000
Aug 04 01:44:16 t14 kernel: audit: type=1400 audit(1691081056.327:2306): apparmor="DENIED" operation="file_inherit" namespace="root//lxd-juju-confined-snap-test_<var-snap-lxd-common-lxd>" profile="snap-update-ns.juju" name="/dev/pts/2" pid=409297 comm="5" requested_mask="wr" denied_mask="wr" fsuid=1000000 ouid=1001000
Aug 04 01:44:16 t14 kernel: audit: type=1400 audit(1691081056.327:2307): apparmor="DENIED" operation="file_inherit" namespace="root//lxd-juju-confined-snap-test_<var-snap-lxd-common-lxd>" profile="snap-update-ns.juju" name="/dev/pts/2" pid=409297 comm="5" requested_mask="wr" denied_mask="wr" fsuid=1000000 ouid=1001000
Aug 04 01:44:16 t14 kernel: audit: type=1400 audit(1691081056.327:2308): apparmor="DENIED" operation="file_inherit" namespace="root//lxd-juju-confined-snap-test_<var-snap-lxd-common-lxd>" profile="snap-update-ns.juju" name="/dev/pts/2" pid=409297 comm="5" requested_mask="wr" denied_mask="wr" fsuid=1000000 ouid=1001000
Aug 04 01:44:17 t14 kernel: audit: type=1400 audit(1691081057.923:2309): apparmor="DENIED" operation="mkdir" namespace="root//lxd-juju-confined-snap-test_<var-snap-lxd-common-lxd>" profile="snap.juju.juju" name="/home/ubuntu/.local/" pid=409272 comm="juju" requested_mask="c" denied_mask="c" fsuid=1001000 ouid=1001000