Move configuration based properties into configuration methods

[Claudenw]

Currently we have code like

    autoCreateTables = config.getBoolean(BigQuerySinkConfig.TABLE_CREATE_CONFIG);
    upsertDelete = config.getBoolean(BigQuerySinkConfig.UPSERT_ENABLED_CONFIG)
        || config.getBoolean(BigQuerySinkConfig.DELETE_ENABLED_CONFIG);

    useCredentialsProjectId = config.getBoolean(BigQuerySinkConfig.USE_CREDENTIALS_PROJECT_ID_CONFIG);
    useStorageApi = config.getBoolean(BigQuerySinkConfig.USE_STORAGE_WRITE_API_CONFIG);
    useStorageApiBatchMode = useStorageApi && config.getBoolean(BigQuerySinkConfig.ENABLE_BATCH_MODE_CONFIG);

    retry = config.getInt(BigQuerySinkConfig.BIGQUERY_RETRY_CONFIG);
    retryWait = config.getLong(BigQuerySinkConfig.BIGQUERY_RETRY_WAIT_CONFIG);
    allowNewBigQueryFields = config.getBoolean(BigQuerySinkConfig.ALLOW_NEW_BIGQUERY_FIELDS_CONFIG);
    allowRequiredFieldRelaxation = config.getBoolean(BigQuerySinkConfig.ALLOW_BIGQUERY_REQUIRED_FIELD_RELAXATION_CONFIG);

Where the configuration logic is scattered across the system in various places.

These should be implemented within the configuration class.

    autoCreateTables = config.autoCreateTables();
    upsertDelete = config.upsertDelete();

    useCredentialsProjectId = config.useCredentialsFromProjectId();
    useStorageApi = config.useStorageApi();
    useStorageApiBatchMode = config.useStorageApiBatchMode();

    RetryConfig retryCfg = config.getRetryConfig();
    allowNewBigQueryFields = config.allowNewBigQueryFields();
    allowRequiredFieldRelaxation = config.allowRequiredFieldRelaxation();

Where RetryConfig is

Interface RetryConfig {
   int getCount();
   long getDelay()
}

That will encapsulate the conversions and logic gymnastics into the config class keep the code cleaner.