[Improvement] Ignore bash/bash-script processes in single_process_type check

[martin-mat]

Is your feature request related to a problem? Please describe.
single_process_type checks for a single process to run in a container. It currently also allows init processes beside an application process. In case that a process is started using a bash script, the test fails on it.

Describe the solution you'd like
Allow bash process and scripts to run in a container. In some cases CNFs use bash/bash scripts to handle sigterm.