[collection] environment do not respect flink-conf.yaml.

When the Flink master is set to -[auto] and- [collection], flink-conf.yaml (from the FLINK_CONF_DIR environment variable, or the \--flink-conf-dir option of the job server) is disregarded.

-This can result in some confusing behavior. For example, when [auto] creates a local environment, an empty Configuration() object is used.-

-[https://github.com/apache/beam/blob/dd71c9ac472b62ff3598d3db47b0f26985bbc82a/runners/flink/src/main/java/org/apache/beam/runners/flink/FlinkExecutionEnvironments.java#L82-L85](https://github.com/apache/beam/blob/dd71c9ac472b62ff3598d3db47b0f26985bbc82a/runners/flink/src/main/java/org/apache/beam/runners/flink/FlinkExecutionEnvironments.java#L82-L85)-

Imported from Jira [BEAM-11612](https://issues.apache.org/jira/browse/BEAM-11612). Original Jira may contain additional context.
Reported by: ibzib.