QA:Testcase partitioning webui guided shrink

Associated release criterion
This test case is associated with the Fedora_42_Final_Release_Criteria#storage-volume-resize release criterion. If you are doing release validation testing, a failure of this test case may be a breach of that release criterion. If so, please file a bug and nominate it as blocking the appropriate milestone, using the blocker bug nomination page.

Description

This test case tests whether the webui-based installer can successfully resize existing storage volume(s) and automatically partition in the freed-up space using the guided partitioning path.

Setup

1. Prepare a test system with a working, supported storage device of sufficient size for a Fedora install, and a Fedora installation medium that uses the webui-based installer - e.g. Fedora Workstation live, on Fedora 42 and above.
2. Ensure the target device contains at least one existing storage volume, ideally an existing OS installation.
3. Ensure there is enough free space within at least one of the volumes that shrinking the volume will provide enough free space for a Fedora installation.

How to test

1. Boot the webui-based installer using any available means, e.g. Fedora Workstation live on Fedora 42+.
2. Proceed to the installer's "Installation method" screen, making sensible choices.
3. Ensure only the target device you prepared is selected as the "Destination".
4. Ensure the "Share disk with other operating system" option is selected and the "Reclaim space" checkbox is checked, and click Next.
5. On the Reclaim space screen, choose to resize the existing storage volume, creating sufficient free space for the installation.
6. Complete the installation process, making sensible selections for all other installer options.
7. Boot the installed system.

Expected Results

1. The storage volume on the target disk that was chosen to be resized should now be the chosen size.
2. The pre-existing contents of the resized volume should not be disturbed.
3. The expected partition layout should be created on the target device(s).
4. The install process should complete successfully and the installed system should boot as expected.