MediaMetrics: Prune audio analytics dump

Remove duplication in TransactionLog and TimeMachine
due to truncation at the dumpsys.  These can still be obtained
by the --all option.

Slight increase in the recorded queue from 2000 to 2500 items.

Flag: EXEMPT bugfix
Test: adb shell dumpsys media.metrics
Test: atest mediametrics_tests
Bug: 367363495
Change-Id: I715b0bb3e580636ac6ba6a47e39112ab9cfaa937