Installing packages on JeOS inside a VM with 1GiB RAM from YaST fails.

Spawning the RPM process fails as it runs out of memory as the kernel's default
overcommit policy does not allow forking the YaST process due a lot of private
memory being used.

## Observation

openQA test in scenario
opensuse-Tumbleweed-JeOS-for-kvm-and-xen-x86_64-jeos@64bit_virtio fails in
[yast2_i](https://openqa.opensuse.org/tests/972266/modules/yast2_i/steps/33)

## Test suite description
Maintainer: fvogt, mnowak

Start JeOS from the HDD image, configure it using the firstboot wizard and then
run basic tests. console=tty0 added as needed for aarch64.

## Reproducible

Fails since (at least) Build
[20190329](https://openqa.opensuse.org/tests/895647)

## Expected result

Last good: (unknown) (or more recent)

## Further details

Always latest result in this scenario:
[latest](https://openqa.opensuse.org/tests/latest?version=Tumbleweed&distri=opensuse&arch=x86_64&test=jeos&flavor=JeOS-for-kvm-and-xen&machine=64bit_virtio)