Video player seek settings: add modifiers

Description

As the seek time delays will be made customizable, it would be great to add settings for the keyboard arrow with modifiers (CTRL, ALT, SHIFT). These settings should only be shown when a keyboard is detected.

resources.configuration.keyboard seems to be a pretty accurate value to detect the keyboard presence.

As the settings for the controls are growing in size, we should display them in a PreferenceCategory if possible (in a BottomSheetFragment).

App mode

Smartphone

TV