Calling ‘rpm -i’ might fail at some Linux

[andreas-roehler]

Scripts in directory ‘podman_cli’ check for an installed podman
calling ‘rpm -i’. As not all Linux systems have rpm installed, that
might fail. Suggest to use POSIX command ‘type’ instead.

There is also an error WRT test in following line. Replace double
brackets by single one.

Example error when running podman_pause_unpause.sh:

./podman_pause_unpause.sh: 24: rpm: not found
./podman_pause_unpause.sh: 25: [[: not found

[rhatdan]

Please open an PR to fix the way you want.