Potential bug in Shenzhen RawDataLoader

Database checks for DataModules containing the Indian dataset fail due to incorrectly generated Indian sample paths. The Indian dataset reuses the RawDataLoader from Shenzhen Datamodule with a config_variable, however the config_variable seems to be ignored when calling the Shenzhen RawDataLoader. Instead the Shenzhen CONFIGURATION_KEY_DATADIR is used to generate the Indian dataset sample paths.