:_input_key.attack: and :_input_key.use: show "Unassigned" on touchscreen

How to reproduce

/tellraw @a {"rawtext":[{"text":":_input_key.attack: :_input_key.use:"}]}

Expected behavior

Observed behavior

Since the entire point of this feature is to show controls in a platform-agnostic way, this issue makes these inputs effectively unusable.