Squashed revert of customization changes

These changes no longer work since ThemePicker switched to the new UI.
They will have to be reimplemented in the new code.

Revert "ThemePicker: Allow text scroll in options title"

This reverts commit 78101bd6.

Revert "ThemePicker: Use the new material switch to match with settings"

This reverts commit 80a03b39.

Revert "ThemePicker: Many UI / layout consistency fixes & improvements"

This reverts commit effcdd3d.

Revert "ThemePicker: Show our apps in icon previews"

This reverts commit 7d7505ce.

Revert "ThemePicker: Vertically center the text of customization options"

This reverts commit 921a622d.

Revert "ThemePicker: Bring back fonts, icon pack, shape customization"

This reverts commit 8d4c0a3b.

Change-Id: I41200d9152f6f772e09ead2afdc0bb7d8166c37e