Atom: Add A2DP playback related atoms to StatsLog

* BluetoothA2dpPlaybackStateChanged:
  - Logged when A2DP playback state changed for individual devices
* BluetoothA2dpCodecConfigChanged
  - Logged when A2DP codec configuration changed for individual devices
* BluetoothA2dpCodecCapabilityChanged
  - Logged when A2DP codec capability changed for individual devices
* BluetoothActiveDeviceChanged
  - Logged when A2DP/HFP/HEARNING_AID active device changed
* BluetoothA2dpAudioOverrunReported
  - Logs when A2DP failed send encoded data to the remote device fast
    enough such that the transmit buffer queue is full and we have to
    drop data
* BluetoothA2dpAudioUnderrunReported
  - Logs when A2DP failed to read from PCM source
* BluetoothDeviceRssiReported
  - Logged when remote device's RSSI level is reported by the controller
* BluetoothDeviceFailedContactCounterReported
  - Logged when ACL transmit queue was flushed by the controller
  - This is normally disabled unless we set automatic flush timeout was
    set to a non-zero value
  - However, when this event is reported, the connection quality must
    be very bad
* BluetoothDeviceTxPowerLevelReported
  - Logged when transmit power level is reported for a particular
    connection

Bug: 112969790
Test: make, testdrive with statsd
Change-Id: I7deb85567630fae75be733df21b45f9c6bcf9e17
Merged-In: I7deb85567630fae75be733df21b45f9c6bcf9e17
(cherry picked from commit c27040ae)