[fix][test] Make base test class method protected so that it passes R…

…eportUnannotatedMethods validation (#21976)

(cherry picked from commit 67354b1)

pulsar-broker/src/test/java/org/apache/pulsar/broker/auth/MockedPulsarServiceBaseTest.java

@@ -720,14 +720,14 @@ protected void sleepSeconds(int seconds){
         }
     }
 
-    public static void reconnectAllConnections(PulsarClientImpl c) throws Exception {
+    private static void reconnectAllConnections(PulsarClientImpl c) throws Exception {
         ConnectionPool pool = c.getCnxPool();
         Method closeAllConnections = ConnectionPool.class.getDeclaredMethod("closeAllConnections", new Class[]{});
         closeAllConnections.setAccessible(true);
         closeAllConnections.invoke(pool, new Object[]{});
     }
 
-    public void reconnectAllConnections() throws Exception {
+    protected void reconnectAllConnections() throws Exception {
         reconnectAllConnections((PulsarClientImpl) pulsarClient);
     }