[#76422752] Add the ability to ensure supported kernel

Ubuntu has [deprecated](https://wiki.ubuntu.com/1204_HWE_EOL) all hardware enablement (HWE) kernels which are basically the kernels for newer releases backported to this release. They are named with suffixes of _lts-quantal_, _lts-raring_, _lts_saucy_ and those kernels are only supported until 14.04.1 is released (Aug 8, 2014)

As we are using the original kernel series supplied with 12.04 and that is still supported until April 2017, we don't need to do anything, and this PR is actually a NOOP. However this PR ensures that if `hwe-support-status` changes in future, our kernel will be updated and serves as a model for other environments where we _do_ need to make this change.

```
ssharpe@ci-master-1:~$ hwe-support-status --verbose
You are not running a system with a Hardware Enablement Stack. Your
system is supported until April 2017.
```

If we did upgrade to _lts-trusty_ packages, then we would still be supported until April 2017 (as that is the EOS for Ubuntu 12.04 Precise)
I don't have a good answer for that, but I have lots of information.

The best situation for us would be to use the kernel from Precise 12.04.0 or 12.04.1, because that is the supported release for Precise. The reason for newer kernels is claimed to be "support for newer hardware", which I don't actually think we need. I believe we have used the newer kernels in the past because we wanted docker support somewhere, but that's not why we have them in the GOV.UK environments.

The kernel series you get is defined by how your machine is created and updated. If you start from 12.04.0 or 12.04.1 media, you will stay within the original supported kernel series. The only way to get one of these newer kernels is to deliberately install it. That's why these CI machines are fine.

However if you start from 12.04.2, 12.04.3 or 12.04.4 media when you build your VM template, then you will get the lts-quantal, lts-raring or lts-saucy kernel by default, which unfortunately puts you in the position some of our environments are in.

So because we have inconsistent templates across our many many environments, we have inconsistent kernels. We're going to be doing some work to fix that, so while I think we should upgrade anything that's unsupported to a supported release, I'm not convinced that we should upgrade things that are supported to a different supported release. There's no real reason that our CI environment has to have the same kernel as our GOV.UK Production environment.

However, I would argue there is a different reason for Preview and Production to be on the same series, even if, for example, we find that one is on 12.04.1 and the other is on 12.04.5 - they are both supported but for dev/prod parity I would argue that they should be made to match.