Fix up playback service on wear

[mchowning]

Description

It seems that I left more than a few loose ends when I switched the watch app away from media3 to using the same playback setup as the phone app. The biggest thing I missed was updating the service declaration in wear's manifest file. This meant that the OS wasn't being informed when Pocket Casts was performing playback.

Less critically, I left the old service file and all of the DI setup for it. This PR cleans that up since we'll just switch this to media3 when we do the switch with the phone app.

Note
This PR builds on top of #881, so we probably want to merge that one first.

Testing Instructions

1. Start playing an episode on a pixel watch/emulator
2. Go to the watch's home screen
3. Observe that the playback icon is active (see screencast below)

Screenshots or Screencast

Screen.Recording.2023-04-13.at.9.21.42.PM.mov

Checklist

• If this is a user-facing change, I have added an entry in CHANGELOG.md
• I have considered whether it makes sense to add tests for my changes
• All strings that need to be localized are in modules/services/localization/src/main/res/values/strings.xml
• Any jetpack compose components I added or changed are covered by compose previews

[mchowning]

I added this POST_NOTIFICATIONS permission to stay consistent with the phone app. The other changes to the permissions are just reordering them to be alphabetical.

[ashiagr]

The biggest thing I missed was updating the service declaration in wear's manifest file.

I, too, share the responsibility for not noticing it.

I confirm that the playback icon is active on watch's home screen when media is playing.