Wifi usability: Add trigger type of Wifi unusable events into stats collection

    LABEL_BAD = 2;

  }

  enum UsabilityStatsTriggerType {

    // Default/Invalid event

    TYPE_UNKNOWN = 0;

    // There is a data stall from tx failures

    TYPE_DATA_STALL_BAD_TX = 1;

    // There is a data stall from rx failures

    TYPE_DATA_STALL_TX_WITHOUT_RX = 2;

    // There is a data stall from both tx and rx failures

    TYPE_DATA_STALL_BOTH = 3;

    // Firmware generated an alert

    TYPE_FIRMWARE_ALERT = 4;

  }

  // The current wifi usability state

  optional Label label = 1;

  // The list of timestamped wifi usability stats

  repeated WifiUsabilityStatsEntry stats = 2;

  // What event triggered WifiUsabilityStats.

  optional UsabilityStatsTriggerType trigger_type = 3;

}

message DeviceMobilityStatePnoScanStats {