Addition for <https://github.com/emilk/egui/pull/3847>
In previous one i only fixed crash occurring with Wgpu backend. This
fixes crash with Glow backend as well.
I only tested this change with android so most things i changed are
behind ```#[cfg(target_os = "android")]```.
Both fixes are dirty thought. As
<https://github.com/emilk/egui/pull/3172> says that "The root viewport
is the original viewport, and cannot be closed without closing the
application.". So they break rules i guess? But i can't think about
better solution for now.
Closes <https://github.com/emilk/egui/issues/3861>.