[all] create name convention for layout IDs

[mtrakal]

There is no convention for layout view ids!
In your sample code are somerimes camelCase, sometimes snake_case underscope ids. It make a mess. So please use only one and everywhere same name convention.

For me is prefered camelCase (due to kotlinx) with some prefix like v (view).

What is Google's prefered code style and why developers in Google don't use same style? :/

https://github.com/googlesamples/android-architecture/blob/todo-mvp-dagger/todoapp/app/src/main/res/layout/addtask_act.xml#L45
android:id="@+id/coordinatorLayout"

https://github.com/googlesamples/android-architecture/blob/todo-mvp-dagger/todoapp/app/src/main/res/layout/addtask_frag.xml#L31
android:id="@+id/add_task_title"