yaml: virtio: AGL: wrap domain-specific variables under switches

[rshym]

This commit adds files missed by b7b0622561195d0f6012c3668fd8a7a5ecc28205.

Fixes: b7b0622561195d0f6012c3668fd8a7a5ecc28205.

[rshym]

Not needed 'XT_DOMU_DTB_NAME' removed from the virtio.yaml. The commit message was reworked. PR was rebased on the latest master.

[rshym]

genuine question: is AGL build viable at all? I.e. do we need it? Was it tested in last year?

IMO, prod-devel-rcar with AGL is not compilable right now due to the following reasons:

• AGL sources are dunfell-based;
• android-related part of the image needs to be aligned with regular prod-devel.yaml.

To fix this we need to update AGL to a Kirkstone based release and update Android-related part.

So, before the start of all the latest updates to agl.yaml, I decided, that I have two options:

• do not touch agl.yaml, and pull all updates only when we will update the AGL part of the yaml;
• apply all changes together with all other yamls, despite AGL-related part is not compilable.

I decided to apply changes now,when I understand what I'm doing.

[rshym]

Ack is added. Smoke-tested.