add javadoc to a method in android/GT_SDK/gtrsdk/src/main/java/com/tencent/wstt/gt/collector/monitor/MonitorManager.java

Hi there, when I was reading the code of the function "private AbsMonitor createMonitor(String name)" in android/GT_SDK/gtrsdk/src/main/java/com/tencent/wstt/gt/collector/monitor/MonitorManager.java, I found it has no Javadoc. I would like to contribute by adding “get the   default monitor for the element.". Can you please check if this is correct? Thanks.



