[Service] Make it possible to use non-auto sizes for volumes with adjust_by_ram

[ancorgs]

Problem

In Agama a volume can have automatic sizes based on one or several of the following reasons:

• Snapshots
• Fallbacks from other volumes (eg. "/" max size can exist or not based on the existence of "/home")
• Size of the RAM

But the third one was not working because it was impossible to set the sizes manually for volumes with the property adjust_by_ram in their corresponding outline.

Solution

This sets the new YaST setting ignore_adjust_by_ram if the user has decided to manually enforce sizes. So now it's possible to honor the automatic size or to use custom sizes instead.

Using the automatic size

The table	The form

Forcing manual sizes

The table	The form

To get some background on how this functionality compares to the traditional YaST checkbox "Enlarge to RAM Size for Suspend", see the dedicated section at the description of #1081.

Additionally, this pull request enables adjust_by_ram for swap at the Tumbleweed product, to raise awareness and get feedback.

Testing

• Added a new unit test
• Tested manually (see screenshots above)

Dependencies

Needs yast/yast-storage-ng#1376 at yast2-storage-ng, which implies the corresponding rpm dependency has been updated.