QA:Testcase CoreOS kernel tuning sysctl

Description

Install Fedora CoreOS and tune a kernel parameter under /proc/sys as described in documentation.

Setup

1. Download and verify the latest FCOS next image (pick the right image for your environment).

How to test

1. Create an Ignition file. When writing the configuration, tune a kernel parameter under /proc/sys by adding to /etc/sysctl.d/90-sysrq.conf. The documentation alters the bits for SysRq key but feel free to change another parameter.
2. Launch your Fedora CoreOS system using this Ignition file. See the Quickstart and the provisioning docs for a guide how to launch FCOS in most environments (bare metal, virtual, cloud, etc).

Expected Results

1. You can SSH successfully into your FCOS system.
2. The parameter(s) specified in the ignition file can be seen in /proc/sys and the system behaviour is changed accordingly.
3. The changes in /proc/sys persist through reboots.
4. The linked documentation makes sense, nothing is obviously missing, and the instructions are clear.