fix: Add default VSS

[doosuu]

In case there is no VSS explicitly given by the AppManifest, a fallback is provided. This is needed because we do not have a dependency resolver yet and KUKSA DataBroker needs a vss path to be mounted.

[github-actions]

Coverage: sdk-installer

File	Coverage	Lines	Branches
All files	25%	41%	9%	❌
sdk-installer/src/run.py	19%	29%	9%	❌

Minimum allowed coverage is 80%

Generated by 🐒 cobertura-action against 6be4671

[github-actions]

Coverage: grpc-interface-support

File	Coverage	Lines	Branches
All files	51%	62%	40%	❌
grpc-interface-support/src/conan_helper.py	64%	60%	68%	❌
grpc-interface-support/src/util/__init__.py	23%	23%	0%	❌
grpc-interface-support/src/util/templates.py	28%	28%	0%	❌

Minimum allowed coverage is 80%

Generated by 🐒 cobertura-action against 6be4671

[github-actions]

Coverage: setup

File	Coverage	Lines	Branches
All files	100%	100%	100%	✅

Minimum allowed coverage is 80%

Generated by 🐒 cobertura-action against 6be4671

[github-actions]

Coverage: vehicle-model-lifecycle

File	Coverage	Lines	Branches
All files	87%	90%	84%	✅
vehicle-model-lifecycle/src/download_vspec.py	96%	98%	95%	✅
vehicle-model-lifecycle/src/generate_model.py	54%	59%	50%	❌

Minimum allowed coverage is 80%

Generated by 🐒 cobertura-action against 6be4671

[dennismeister93]

lgtm