Revert "Make idle chromecasts appear as idle instead of off"

[emontnemery]

Reverts #61786

The change is not good because chrome casts running an app but not playing media can no lonegr be distinguished from chromecasts not running any app.

We should probably add a new state "Running app" or similar to the base MediaPlayerEntity

Fixes: #65853

[sdrapha]

Is that reversion gonna break the ability to change volume on google home devices while not playing anything? at least that was a big improvement from the previous change, I don't want to loose that.

[pgsylvestre]

Can we make this an option and let users decide? I liked the fact that the true status was shown ie"backdrop' when not actually off. And, as @sdrapha said, we can no longer set volumes prior use with an 'off' status. Thank You

[n00bcodr]

I second @sdrapha @pgsylvestre I have always missed the ability to change the volume without actually turning on the google home device. I was very happy when we were finally able to do it.

[TheFes]

I don't agree with the argument that with the state always being idle you can not see if it is really idle or in an app which is not playing anything.
This is clearly shown in the attributes of the media_player entity.
Example:

entity_id: media_player.slaapkamer_hub
state: idle

volume_level: 0.25
is_volume_muted: false
media_content_id: some.mp3
media_duration: 61.584
media_position: 0
media_position_updated_at: '2022-02-09T13:58:07.849872+00:00'
media_title: 14 - Jongens, Meisjes, Aan De Kant - 62
app_id: CC1AD845
app_name: Default Media Receiver
entity_picture_local: some.jpg
entity_picture: /local/pictures/tags/bijt_ie_in_je_bil.jpg
friendly_name: Slaapkamer Hub
supported_features: 152463

There were also really nice advantages of the player being able, as you could always change volume, or retrieve attributes like the volume_level

[emontnemery]

I agree with the need to control the volume, but I also understand the concerns raised in #65853
Please help by suggesting solutions in this discussion: home-assistant/architecture#666