FIX: InvalidOperationException thrown when entering PlayMode if Project-wide Input Action Asset changes didn't save (ISX-1953) (#1907)

* FIX: exception thrown due to ActionMap being in a bad state after deleting/resetting it. Error occurs because "reset" change wasn't saved to the asset and didn't correctly de-serialized after domain reload. Adding extra calls to SaveAssetOnFocusLost() ensures asset is properly saved

Author: timkeo

Packages/com.unity.inputsystem/CHANGELOG.md

@@ -17,6 +17,7 @@ however, it has to be formatted properly to pass verification tests.
 - Fixed an issue where `System.ObjectDisposedException` would be thrown when deleting the last ActionMap item in the Input Actions Asset editor.
 - Fixed DualSense Edge's vibration and light bar not working on Windows
 - Fixed Project-wide Actions asset failing to reload properly after deleting project's Library folder.
+- Fixed an issue where `System.InvalidOperationException` is thrown when entering PlayMode after deleting an ActionMap from Project-wide actions and later resetting it.
 
 ### Changed
 - For Unity 6.0 and above, when an `EventSystem` GameObject is created in the Editor it will have the

Packages/com.unity.inputsystem/InputSystem/Editor/UITKAssetEditor/InputActionsEditorSettingsProvider.cs

@@ -76,6 +76,9 @@ public override void OnDeactivate()
                 m_RootVisualElement.UnregisterCallback<FocusInEvent>(OnEditFocus);
             }
 
+            // Make sure any remaining changes are actually saved
+            SaveAssetOnFocusLost();
+
             // Note that OnDeactivate will also trigger when opening the Project Settings (existing instance).
             // Hence we guard against duplicate OnDeactivate() calls.
             if (m_HasEditFocus)
@@ -272,6 +275,8 @@ private void ModeChanged(PlayModeStateChange change)
                     SetObjectFieldEnabled(true);
                     break;
                 case PlayModeStateChange.ExitingEditMode:
+                    // Ensure any changes are saved to the asset; FocusLost isn't always triggered when entering PlayMode.
+                    SaveAssetOnFocusLost();
                     SetObjectFieldEnabled(false);
                     break;
                 case PlayModeStateChange.EnteredPlayMode: