android: fix crash if UserInfo is not set

Fixes: https://github.com/jitsi/jitsi-meet-sdk-samples/issues/11

android/sdk/src/main/java/org/jitsi/meet/sdk/JitsiMeetConferenceOptions.java

         dest.writeString(token);
         dest.writeBundle(colorScheme);
         dest.writeBundle(featureFlags);
-        dest.writeBundle(userInfo.asBundle());
+        dest.writeBundle(userInfo != null ? userInfo.asBundle() : new Bundle());
         dest.writeByte((byte) (audioMuted == null ? 0 : audioMuted ? 1 : 2));
         dest.writeByte((byte) (audioOnly == null ? 0 : audioOnly ? 1 : 2));
         dest.writeByte((byte) (videoMuted == null ? 0 : videoMuted ? 1 : 2));