handle input method visibility for android

[mokurin000]

Is your feature request related to a problem? Please describe.
generated demo app with cargo-mobile2, everyrhing works except for soft keyboard

Describe the solution you'd like
https://developer.android.com/develop/ui/views/touch-and-input/keyboard-input/visibility
https://developer.android.com/ndk/reference/group/native-activity#anativeactivity_showsoftinput
https://developer.android.com/ndk/reference/group/native-activity#anativeactivity_hidesoftinput

https://docs.rs/android-activity/0.5.1/android_activity/struct.AndroidApp.html#method.show_soft_input

Describe alternatives you've considered
rust-windowing/winit#1823

Additional context
when focusing on a widget, users may want it's not covered by soft keyboard

#2975 cc @hanxiaohuivc

[DrSloth]

I am also very interested in this. The softkeyboard can be opened when going through JNI but it doesn't work well.

[ElhamAryanpur]

I am also interested, I have tried android activity's show_soft_input but didn't work out. Everything else works out fine, just soft keyboard is the issue on my end