Remove panicking in Android's HasRawWindowHandle

Instead we now just return a NULL handle, and warn that the native window couldn't be found.

src/platform_impl/android/mod.rs

@@ -595,7 +595,7 @@ impl Window {
         if let Some(native_window) = ndk_glue::native_window().as_ref() {
             handle.a_native_window = unsafe { native_window.ptr().as_mut() as *mut _ as *mut _ }
         } else {
-            panic!("Cannot get the native window, it's null and will always be null before Event::Resumed and after Event::Suspended. Make sure you only call this function between those events.");
+            log::warn!("Cannot get the native window while the application is suspended (between Event::Suspended and Event::Resumed).");
         };
         RawWindowHandle::AndroidNdk(handle)
     }

src/window.rs

@@ -889,8 +889,7 @@ unsafe impl raw_window_handle::HasRawWindowHandle for Window {
     ///
     /// ## Platform-specific
     ///
-    /// - **Android:** Only available after receiving the Resumed event and before Suspended. *If you*
-    /// *try to get the handle outside of that period, this function will panic*!
+    /// - **Android:** Not available between receiving the Suspended and Resumed events.
     fn raw_window_handle(&self) -> raw_window_handle::RawWindowHandle {
         self.window.raw_window_handle()
     }