osbuild-pipeline: pass default image size into pipeline

When creating a pipeline with the default image size, the size should no
longer be set to 0. Instead, the size is fetched using the distro
function GetSizeForOutputType which can return the default image size
for a given image type. This size can then be passed into the pipeline.

cmd/osbuild-pipeline/main.go

@@ -102,7 +102,8 @@ func main() {
 		panic("Could not depsolve build packages: " + err.Error())
 	}
 
-	pipeline, err := d.Pipeline(blueprint, nil, packageSpecs, buildPackageSpecs, checksums, archArg, imageType, 0)
+	size := d.GetSizeForOutputType(imageType, 0)
+	pipeline, err := d.Pipeline(blueprint, nil, packageSpecs, buildPackageSpecs, checksums, archArg, imageType, size)
 	if err != nil {
 		panic(err.Error())
 	}