MediaMetrics: Update dumpsys parameters

Make --prefix and --since work for analytics.

Test: adb shell dumpsys media.metrics --all
Test: adb shell dumpsys media.metrics --clear
Test: adb shell dumpsys media.metrics --heap
Test: adb shell dumpsys media.metrics --help
Test: adb shell dumpsys media.metrics --prefix c
Test: adb shell dumpsys media.metrics --prefix audio.volume
Test: adb shell dumpsys media.metrics --since -100
Test: adb shell dumpsys media.metrics --unreachable
Bug: 149850236
Change-Id: Id3e0cb6fe789027b5d5c86cce93ce07f636736bf