Minor updates to the Spawnable Entity Aliases in response to PR feedback.

Signed-off-by: AMZN-koppersr <82230785+AMZN-koppersr@users.noreply.github.com>

Code/Framework/AzFramework/Tests/Spawnable/SpawnableEntitiesManagerTests.cpp

@@ -101,6 +101,8 @@ namespace UnitTest
     class SpawnableEntitiesManagerTest : public AllocatorsFixture
     {
     public:
+        constexpr static AZ::u64 EntityIdStartId = 40;
+
         void SetUp() override
         {
             AllocatorsFixture::SetUp();
@@ -156,7 +158,7 @@ namespace UnitTest
             {
                 auto entry = AZStd::make_unique<AZ::Entity>();
                 entry->AddComponent(aznew SourceSpawnableComponent());
-                entry->SetId(AZ::EntityId(40 + i));
+                entry->SetId(AZ::EntityId(EntityIdStartId + i));
                 entities.push_back(AZStd::move(entry));
             }
         }
@@ -175,13 +177,13 @@ namespace UnitTest
                     auto entry = AZStd::make_unique<AZ::Entity>();
                     if (i != 0)
                     {
-                        entry->AddComponent(aznew TargetSpawnableComponent(AZ::EntityId(40 + i - 1)));
+                        entry->AddComponent(aznew TargetSpawnableComponent(AZ::EntityId(EntityIdStartId + i - 1)));
                     }
                     else
                     {
                         entry->AddComponent(aznew TargetSpawnableComponent());
                     }
-                    entry->SetId(AZ::EntityId(40 + i));
+                    entry->SetId(AZ::EntityId(EntityIdStartId + i));
                     entities.push_back(AZStd::move(entry));
                 }
             }

Code/Framework/AzToolsFramework/AzToolsFramework/Entity/PrefabEditorEntityOwnershipService.cpp

@@ -415,8 +415,7 @@ namespace AzToolsFramework
         {
             // Construct the runtime entities and products
             bool readyToCreateRootSpawnable = m_playInEditorData.m_assetsCache.IsActivated();
-            if (!readyToCreateRootSpawnable &&
-                !m_playInEditorData.m_assetsCache.Activate(Prefab::PrefabConversionUtils::PlayInEditor))
+            if (!readyToCreateRootSpawnable && !m_playInEditorData.m_assetsCache.Activate(Prefab::PrefabConversionUtils::PlayInEditor))
 
             {
                 AZ_Error("Prefab", false, "Failed to create a prefab processing stack from key '%.*s'.", AZ_STRING_ARG(Prefab::PrefabConversionUtils::PlayInEditor));

Code/Framework/AzToolsFramework/AzToolsFramework/Prefab/Spawnable/PrefabProcessorContext.cpp

@@ -38,6 +38,7 @@ namespace AzToolsFramework::Prefab::PrefabConversionUtils
         if (!m_prefabNames.contains(name))
         {
             m_prefabNames.emplace(AZStd::move(name));
+            // If currently iterating add to pending queue to avoid invalidating the container that's being iterated over.
             PrefabContainer& container = m_isIterating ? m_pendingPrefabAdditions : m_prefabs;
             container.push_back(AZStd::move(document));
             return true;
@@ -47,6 +48,8 @@ namespace AzToolsFramework::Prefab::PrefabConversionUtils
 
     void PrefabProcessorContext::ListPrefabs(const AZStd::function<void(PrefabDocument&)>& callback)
     {
+        // Enable iterating state so the prefab container doesn't get invalided. Enabling this flag will cause new prefabs
+        // to be stored in a temporary buffer that can be moved into the regular prefab container after iterating.
         m_isIterating = true;
         for (PrefabDocument& document : m_prefabs)
         {