Reset prefab system in all prefab benchmarks

Code/Framework/AzToolsFramework/Tests/Prefab/Benchmark/PrefabInstantiateBenchmarks.cpp

@@ -41,6 +41,10 @@ namespace Benchmark
             {
                 newInstances[instanceCounter] = m_prefabSystemComponent->InstantiatePrefab(templateToInstantiateId);
             }
+            
+            state.PauseTiming();
+            ResetPrefabSystem();
+            state.ResumeTiming();
         }
 
         state.SetComplexityN(numInstances);

Code/Framework/AzToolsFramework/Tests/Prefab/Benchmark/SpawnableCreateBenchmarks.cpp

@@ -36,7 +36,8 @@ namespace Benchmark
 
             AzFramework::Spawnable spawnable;
             AzToolsFramework::Prefab::SpawnableUtils::CreateSpawnable(spawnable, prefabDom);
-
+            
+            ResetPrefabSystem();
             state.ResumeTiming();
         }