Run OS tests in stability mode

The second mode is stability mode - for testing the os stability. In this case you should put the number of cycles (for example, to run 1000 cycles - ./test-script.sh 1000). And now after script is finished the common log will be placed to the /var/tmp/os-stability.<ISO TIME>.txt file, and you will find logs about separate cycles in ostest-test.<N>.txt form in the /var/tmp folder, where <N> - is a cycle number.