Model picker taps (mp:/mpg:/mpv:/mm:/mc:/mb/mx/mg:) never went through the
callback allowlist, so a group member who is not allowlisted could tap the
owner's /model picker and switch the owner's session or config model. Gate
the handler on _callback_authorized like the choice-picker, approval and
clarify buttons, before any picker state is read.
Ported from #33859 (gateway/platforms/telegram.py) to the plugin adapter.
(cherry picked from commit b002be8feacd09fde0ee9752de7b396d0aac69ba)
999b19b6ed