This is a performance improvement

java/rmi/activation/Activatable/forceLogSnapshot
method waitAllStarted is using recursive sleep to poll 50 restartedObject to be true, we can use modern CountDownLatch to implement blocking-time wait.
Also suggest shorten waiting time to 5 seconds.

java/rmi/activation/Activatable/checkAnnotations
We can subclass ByteArrayOutputStream which support notification when data was written. Also use two thread wait output string and error string to be not null