test/trace_processor/android/android_system_property.textproto

packet {
  timestamp: 1000
  android_system_property {
    values {
      name: "debug.tracing.screen_state"
      value: "2"
    }
    values {
      name: "debug.tracing.device_state"
      value: "some_state_from_sysprops"
    }
  }
}
packet {
  ftrace_events {
    cpu: 1
    event {
      timestamp: 2000
      pid: 1
      print {
        buf: "C|1000|ScreenState|1\n"
      }
    }
    event {
      timestamp: 3000
      pid: 1
      print {
        buf: "N|1000|DeviceStateChanged|some_state_from_atrace\n"
      }
    }
  }
}