Peggy,
The 2nd method is RTSP announce where the encoder initiates a connection and sends .sdp to to Wowza. You don’t need a .sdp file or use StreamManager with this kind of encoder.
The 1st method requires an encoder to generate a .sdp file which is copied to Wowza, then started in StreamManager.
I’m really not sure what is possible in Android, but the 1st method would be more practical.
I don’t have any experience or Wowza example, but a customer posted this solution for publishing from Android
Richard