MediaMetric:Save each item indiviually for AudioPowerUsage am: cfb0ffb0a8 am: 1086035845

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/12190585

Change-Id: Ic4625f3b7b734b6008aee3f48b63629c0d8ecc78