Instead of using the roku.power method, which toggles power,
implement the media_player.turn_on command for the roku component
by calling the new roku.poweron method.
Fixes#28961, but depends on upstream
https://github.com/jcarbaugh/python-roku/pull/53
* Move more constants to const.py
* Import constants directly from const
* ATTR_ENTITY_ID is not defined in media_player
* MEDIA_PLAYER_PLAY_MEDIA_SCHEMA is still in __init__.py
* Correct imports in tts
* PLATFORM_SCHEMA, SCHEMA is still defined in __init__.py
* Pandora imports several services
* Some additional fixes for move of const in media_player
* Fix hound lengths