[Avalonia.Native] Respect info.plist values for setActivationPolicy (#19066)

* [Avalonia.Native] Respect info.plist values

* Only set setActivationPolicy if it's different from the users default

native/Avalonia.Native/src/OSX/app.mm

@@ -30,8 +30,6 @@ ComPtr<IAvnApplicationEvents> _events;
             break;
         }
         
-        [[NSApplication sharedApplication] setActivationPolicy: AvnDesiredActivationPolicy];
-        
         [[NSUserDefaults standardUserDefaults] setBool:NO forKey:@"NSFullScreenMenuItemEverywhere"];
         
         [[NSApplication sharedApplication] setHelpMenu: [[NSMenu new] initWithTitle:@""]];

native/Avalonia.Native/src/OSX/main.mm

@@ -129,14 +129,22 @@ public:
         }
     }
     
-    virtual HRESULT SetShowInDock(int show)  override
+    virtual HRESULT SetShowInDock(int show) override
     {
         START_COM_CALL;
         
         @autoreleasepool
         {
-            AvnDesiredActivationPolicy = show
+            NSApplication* app = [NSApplication sharedApplication];
-                ? NSApplicationActivationPolicyRegular : NSApplicationActivationPolicyAccessory;
+            NSApplicationActivationPolicy requestedPolicy = show
+                ? NSApplicationActivationPolicyRegular
+                : NSApplicationActivationPolicyAccessory;
+            
+            if ([app activationPolicy] != requestedPolicy)
+            {
+                [app setActivationPolicy:requestedPolicy];
+            }
+            
             return S_OK;
         }
     }