[FLINK-11413][Metrics] Reporter filtering using metrics.reporters broken on Java 9+

[mb-datadome]

What is the purpose of the change

Reporter configuration is not working properly on java 9 and above due to a different behavior between java 8 and above about splitAsStream

Brief change log

• add MetricRegistryConfigurationTest.java to cover the different reporter configurations
• fix MetricRegistryConfiguration.java with compatibility with all java version

Verifying this change

This change added tests and can be verified as follows:

• Manually change runtime to java 9 to ensure code is compatible with java 9

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): no
• The public API, i.e., is any changed class annotated with @Public(Evolving): no
• The serializers: no
• The runtime per-record code paths (performance sensitive): no
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Yarn/Mesos, ZooKeeper: no
• The S3 file system connector: no

Documentation

• Does this pull request introduce a new feature? no

[flinkbot]

Thanks a lot for your contribution to the Apache Flink project. I'm the @flinkbot. I help the community
to review your pull request. We will use this comment to track the progress of the review.

Review Progress

• ❌ 1. The [description] looks good.
• ❌ 2. There is [consensus] that the contribution should go into to Flink.
• ❔ 3. Needs [attention] from.
• ❌ 4. The change fits into the overall [architecture].
• ❌ 5. Overall code [quality] is good.

Please see the Pull Request Review Guide for a full explanation of the review process.

Details

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot approve description to approve the 1st aspect (similarly, it also supports the consensus, architecture and quality keywords)
• @flinkbot approve all to approve all aspects
• @flinkbot attention @username1 [@username2 ..] to require somebody's attention
• @flinkbot disapprove architecture to remove an approval