Bloom allows inconsistent distro configuration

[norro]

I just discovered by accident that bloom seems to allow inconsistent specification of the targeted ROS distribution between command line argument and input during the script.

Steps to reproduce:

1. Call bloom providing a certain ROS distro as argument, e.g., bloom-release --rosdistro rolling ...
2. When asked for the ROS release during execution, provide a different ROS distro, e.g., galactic (rolling will be the default answer for the question in this case)

This will lead to a PR changing rolling/distribution.yaml (according to the initial command line argument). The distribution given during execution of the script doesn't seem to have any effect. This might lead to a user assuming he is releasing for galactic, therefor answering subsequent questions accordingly, which will lead to a wrong PR (to the rolling distro in the above example).

So it seems that 2. is pretty much ignored when the distribution is given via command line? I have to say that this was discovered during the initial release of a package. I will try if this is the same when doing subsequent releases once the initial PRs are merged.

This is an example of the above situation.