[daisy Import] throw error msg (#757)
[daisy Import] throw error msg (#757)

* throw error msg to daisy log when import error happens

adjackura/compute-image-tools,GoogleCloudPlatform/compute-daisy,zmarano/compute-image-tools,GoogleCloudPlatform/compute-image-import,zmarano/compute-image-tools,GoogleCloudPlatform/compute-image-tools,adjackura/compute-image-tools,zmarano/compute-image-tools,GoogleCloudPlatform/compute-image-tools,GoogleCloudPlatform/compute-image-import,adjackura/compute-image-tools,GoogleCloudPlatform/compute-image-import,GoogleCloudPlatform/compute-image-tools,GoogleCloudPlatform/compute-daisy