Removed null check for username password for client credentials type.

[vikasrathee-cs]

Removed null check for username password for client credentials type.

For grant type client_credentials, username and password can be null.

[itsankit-google]

it is okay to remove null check because it is not required in certain cases.

But we should also add validation for the type when these configs are required.

[vikasrathee-cs]

it is okay to remove null check because it is not required in certain cases.

But we should also add validation for the type when these configs are required.

As of now, there is no explicit variable defined which calculates whether user is supporting password grant or client_creds. Based on the values, if user name and password are null, it will fallback to client creds automatically. This was done to support DTS use case I guess.

[itsankit-google]

it is okay to remove null check because it is not required in certain cases.
But we should also add validation for the type when these configs are required.

As of now, there is no explicit variable defined which calculates whether user is supporting password grant or client_creds. Based on the values, if user name and password are null, it will fallback to client creds automatically. This was done to support DTS use case I guess.

As discussed offline, this way we will not be able to maintain the extensibility of CDF plugin's ability to support multiple auth types.

We can add a AuthenticationType similar to google-cloud plugins to correctly fix this.

We can also hide certain fields in CDF Plugin UI based on authenticationType.