Merge "Create flag for event scratch buffer nullability" into main

  description: "This flag controls if the callback onDynamicSensorsDisconnected is implemented or not."

  bug: "316958439"

}

flag {

  name: "sensor_event_connection_send_event_require_nonnull_scratch"

  namespace: "sensors"

  description: "This flag controls we allow to pass in nullptr as scratch in SensorEventConnection::sendEvents()"

  bug: "339306599"

}