I got issue with Nexus 10 - 4.2.2. I was testing code below on Galaxy Tab 10.1 with 4.0.4 and it was working fine:
try 
{
    Process proc = Runtime.getRuntime()         
        
To show and hide the system bar and notification bar on 4.2.2 and others:
Hide:
    try
    {
        String command;
        command = "LD_LIBRARY_PATH=/vendor/lib:/system/lib service call activity 42 s16 com.android.systemui";
        Process proc = Runtime.getRuntime().exec(new String[] { "su", "-c", command }, envp);
        proc.waitFor();
    }
    catch(Exception ex)
    {
        Toast.makeText(getApplicationContext(), ex.getMessage(), Toast.LENGTH_LONG).show();
    }
Show:
    try 
    {
         String command;
         command = "LD_LIBRARY_PATH=/vendor/lib:/system/lib am startservice -n com.android.systemui/.SystemUIService";
         Process proc = Runtime.getRuntime().exec(new String[] { "su", "-c", command }, envp);
         proc.waitFor();
    } 
    catch (Exception e) 
    {
          e.printStackTrace();
    }