Change LookupRemoteImage to return error

This carries and replaces #9192

This commit is patch for following comment
// TODO: This method should return the errors instead of masking them and returning false

Signed-off-by: Daehyeok Mun <daehyeok@gmail.com>
Signed-off-by: Michael Crosby <crosbymichael@gmail.com>
It's nice that we have the error here now, but it looks like we don't actually use it other than to check if it's `nil`. Should we bother logging it in this case?