[Commonizer] Logging: Show [Step x of y] only when more than one task is scheduled

^KT-36679

native/commonizer/src/org/jetbrains/kotlin/commonizer/cli/cli.kt

@@ -30,10 +30,11 @@ fun main(args: Array<String>) {
             category.prologue?.let(::println)
 
             sortedTasks.forEachIndexed { index, task ->
-                val logPrefix = if (category.logEachStep) "[Step ${index + 1} of ${sortedTasks.size}] " else ""
+                val logPrefix = if (category.logEachStep && sortedTasks.size > 1) "[Step ${index + 1} of ${sortedTasks.size}] " else ""
                 task.execute(logPrefix)
             }
 
+
             category.epilogue?.let(::println)
         }
     }