Android subsribe remoteStream with h265 will crash when mcu not support h265 codec

[zhangyihui1]

mcu not support h265 codec 1: android join room 2: android publish local stream 3: android subscribe remoteStream with h265

expect : android subscribe failed actual: android app crash

log: 2019-09-17 13:18:08.828 16167-16231/owt.sample.conference E/OWT_CONF: Failed to subscribe Failed to set remote answer sdp: Failed to set remote video description send parameters.

--------- beginning of crash

2019-09-17 13:18:08.829 16167-16248/owt.sample.conference E/AndroidRuntime: FATAL EXCEPTION: pool-6-thread-1 Process: owt.sample.conference, PID: 16167 java.lang.NullPointerException: Attempt to invoke virtual method 'void owt.conference.Subscription.onError(owt.base.OwtError)' on a null object reference at owt.conference.ConferenceClient.onError(ConferenceClient.java:895) at owt.conference.ConferencePeerConnectionChannel.lambda$onSetFailure$23$ConferencePeerConnectionChannel(ConferencePeerConnectionChannel.java:118) at owt.conference.-$$Lambda$ConferencePeerConnectionChannel$SuZqmJsooiK8I2_SjeocaJFNI2E.run(Unknown Source:4) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1162) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:636) at java.lang.Thread.run(Thread.java:784)