JFR: onMetadata(), setStartTime(), setEndTime() lacks test coverage

The following three methods in RemoteRecordingStream class lacks test coverage:

- onMetadata(MetadataEvent)
- setStartTime(Instant)
- setEndTime(Instant)

The implementation of onMetadata, setStartTime, setEndTimedelegates to EventDirectoryStream used by EventStream::openRepository(). It should be sufficient to add sanity tests to open/test/jdk/jdk/jfr/jmx/streaming/TestDelegated.java

The onMetadata fetches configurations, i.e default and profile, using a dedicated JMX call, so the test should check that they are included.