[Android] Change `ndk-glue` to `android-activity` like in Windows-Template

[SakulFlee]

Windowing-Template had some trouble with winit switching from ndk-glue to android-activity in the recent 0.18 version.

Android-activity seems to be much better suited for our needs, and we should make this change globally for all Android-supported projects.

The changes made over at Windowing-Template can be found here.

[create-issue-branch[bot]]

Branch issue-182-_Android_Change_ndk-glue_to_android-activity_like_in_Windows-Template created for issue: [Android] Change ndk-glue to android-activity like in Windows-Template