Unable to detect Unified-Parallel logs that don't start with "Using Parallel" #462
Description
Describe the bug
Discovered while fixing #457, the diarizer is not able to reliably identify Unified-Parallel logs that don't start with "Using Parallel" at the beginning of the file. This means that rollover logs using Unified-Parallel cannot be reliably identified and processed.
To Reproduce
Steps to reproduce the behavior:
Comment out the first line in UnifiedGenerationalEventsTest.testParallelNoDetails() (added in PR for #457) and run the test. (Lines were taken from file attached to #457)
The test does not generate the correct number of events as it was not able to select the Parallel collector from the information provided.
Expected behavior
Parser is able to successfully identify the garbage collector so that it can parse the events properly.
Additional context
Unfortunately, many of the logged events in Parallel logs are also used in other collectors which makes this difficult.