android: renderer_vulkan: Fix crash with surface recreation.

src/video_core/renderer_base.h

@@ -89,6 +89,9 @@ public:
     void RequestScreenshot(void* data, std::function<void(bool)> callback,
                            const Layout::FramebufferLayout& layout);
 
+    /// This is called to notify the rendering backend of a surface change
+    virtual void NotifySurfaceChanged() {}
+
 protected:
     Core::Frontend::EmuWindow& render_window; ///< Reference to the render window handle.
     std::unique_ptr<Core::Frontend::GraphicsContext> context;