Automatic merge from submit-queue

make invocation ReadDockerConfigFile can handle .dockerconfigjson file

**What this PR does / why we need it**:

When **.docker/config.json** is used to authenticate docker registry, the data key **.dockerconfigjson** should be used if we want to save this kind of docker auth data into a secret. So this PR is mainly to make invocation `ReadDockerConfigFile `have ability to read  **.dockerconfigjson** file.
@liggitt