Change WorkManager default clear completed work cleaner timeout

Here is the current default value by pools:

When unspecified the default is 3600s.

The cleanup must be more aggressive so on high throughput we are not creating memory contention.
The cleaning is called every 300s so it is useless to use less than 300s.

The default should be set to 600s and heavy used pool should use 300s.
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Completed work information are cleared earlier to save memory footprint.