Remove old code from SoundSettings not used in new IA.

- remove the old sound settings xml
- merge Sound Dashboard metadata into SiybdSettingsActivity instead
and remove Sound Dashboard.
- remove OtherSoundSettings

Bug: 35764802
Test: make RunSettingsRoboTests
Change-Id: I25bb94b375cfe0277b3c961e4bee6fec9a14fb98
9 files changed