8273541: Cleaner Thread creates with normal priority instead of MAX_P…

…RIORITY - 2

Backport-of: 4e6de5f9defc031158e027bcbbaf6232b8c03d60

src/java.base/share/classes/jdk/internal/ref/CleanerImpl.java

@@ -325,7 +325,7 @@ static ThreadFactory factory() {
 
         public Thread newThread(Runnable r) {
             return InnocuousThread.newThread("Cleaner-" + cleanerThreadNumber.getAndIncrement(),
-                r, Thread.MIN_PRIORITY - 2);
+                r, Thread.MAX_PRIORITY - 2);
         }
     }