MediaMetrics: Fix legacy AudioTrack AudioRecord protos

Client rename of item fields broke statsd logging in server.
Repair to be consistent.

Regression from commit d097981a

Test: record, playback, check media.metrics dumpsys
Test: failure logging patch, all clear.
Bug: 210123187
Change-Id: I9224dcdb01378010fcd0013a50d92b2c9bea1d1c