convert2rhel fails with UNSUPPORTED_KERNEL_MODULES if kernel is included in yum.conf exclude

What were you trying to do that didn't work?

If you include a kernel exclude in /etc/yum.conf such as

~~~

1. grep exclude /etc/yum.conf

exclude=kernel* 

~~~

Then convert2rhel does not pull in the base kernel or kernel-devel modules when it's checking for unsupported kmods which leads to this error where it thinks modules from the kernel package are unsupported:

~~~

========== Overridable (Review and either fix or ignore the failure) ==========
(OVERRIDABLE) ENSURE_KERNEL_MODULES_COMPATIBILITY::UNSUPPORTED_KERNEL_MODULES - Unsupported kernel modules
     Description: Unsupported kernel modules were found
     Diagnosis: The following loaded kernel modules are not available in RHEL:
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/net/ipv4/netfilter/ip_tables.ko.xz
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/drivers/virtio/virtio_pci.ko.xz
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/net/802/stp.ko.xz
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/net/netfilter/nf_nat.ko.xz

<snip>

~~~

Please provide the package NVR for which bug is seen:

How reproducible:

everytime

Steps to reproduce

1. Add exclude=kernel* to /etc/yum.conf

1. Attempt `convert2rhel analyze` to see the error

Expected results

I think it should just grep /etc/yum.conf and warn the user if kernel or kmod are listed in an exclude line.  Alternatively could just ignore kernel/kmod excludes since we have to use kernel packages in a conversion.

Actual results

conversion fails with

~~~

========== Overridable (Review and either fix or ignore the failure) ==========
(OVERRIDABLE) ENSURE_KERNEL_MODULES_COMPATIBILITY::UNSUPPORTED_KERNEL_MODULES - Unsupported kernel modules
     Description: Unsupported kernel modules were found
     Diagnosis: The following loaded kernel modules are not available in RHEL:
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/net/ipv4/netfilter/ip_tables.ko.xz
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/drivers/virtio/virtio_pci.ko.xz
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/net/802/stp.ko.xz
    /lib/modules/3.10.0-1160.102.1.el7.x86_64/kernel/net/netfilter/nf_nat.ko.xz

<snip>

~~~

AC:

1) Ask Charlie why the kernel is excluded