BUG#37644518: Race condition on rpl_opt_tracker [Post-fix]

Fix the compilation warning, escalated to error, on Windows:
```
sql\rpl_opt_tracker.cc(122,1):
error C2220: the following warning is treated as an error
sql\rpl_opt_tracker.cc(113):
warning C26417: Shared pointer parameter 'service_guard' is passed
by reference and not reset or reassigned. Use T* or T& instead
(r.35).
```

To solve the above issue, made the parameter `service_guard`
constant.

Change-Id: Ia4509fd72fe2478abf8465225a7e921dea5a2680

Author: nacarvalho

sql/rpl_opt_tracker.cc

@@ -110,8 +110,8 @@ bool Rpl_opt_tracker::is_replication_replica_enabled() {
   return replication_replica_enabled;
 }
 
-void Rpl_opt_tracker::track(Tracker_service_guard &service_guard, bool enabled,
-                            const std::string &fname,
+void Rpl_opt_tracker::track(const Tracker_service_guard &service_guard,
+                            bool enabled, const std::string &fname,
                             unsigned long long &usage_counter) {
   if (service_guard.is_valid()) {
     service_guard->set_enabled(fname.c_str(), enabled ? 1 : 0);
@@ -121,14 +121,14 @@ void Rpl_opt_tracker::track(Tracker_service_guard &service_guard, bool enabled,
   }
 }
 
-void Rpl_opt_tracker::track_binary_log(Tracker_service_guard &service_guard,
-                                       bool enabled) const {
+void Rpl_opt_tracker::track_binary_log(
+    const Tracker_service_guard &service_guard, bool enabled) const {
   track(service_guard, enabled, s_f_name_binary_log,
         m_opt_option_tracker_usage_binary_log);
 }
 
 void Rpl_opt_tracker::track_replication_replica(
-    Tracker_service_guard &service_guard, bool enabled) const {
+    const Tracker_service_guard &service_guard, bool enabled) const {
   track(service_guard, enabled, s_f_name_replication_replica,
         m_opt_option_tracker_usage_replication_replica);
 }

sql/rpl_opt_tracker.h

@@ -99,7 +99,7 @@ class Rpl_opt_tracker {
     @param fname feature name
     @param usage_counter feature usage counter
   */
-  static void track(Tracker_service_guard &service_guard, bool enabled,
+  static void track(const Tracker_service_guard &service_guard, bool enabled,
                     const std::string &fname,
                     unsigned long long &usage_counter);
 
@@ -113,7 +113,7 @@ class Rpl_opt_tracker {
     @param enabled  true:  tracks as enabled
                     false: tracks as disabled
   */
-  void track_binary_log(Tracker_service_guard &service_guard,
+  void track_binary_log(const Tracker_service_guard &service_guard,
                         bool enabled) const;
 
   /**
@@ -124,7 +124,7 @@ class Rpl_opt_tracker {
     @param enabled  true:  tracks as enabled
                     false: tracks as disabled
   */
-  void track_replication_replica(Tracker_service_guard &service_guard,
+  void track_replication_replica(const Tracker_service_guard &service_guard,
                                  bool enabled) const;
 
   SERVICE_TYPE_NO_CONST(registry_registration) *