[sb] Add new battery icon to ShadeHeaderController

This adds the composable battery to the legacy shade header. Adding it
to the compose header is left as homework for the reader.

Test: manual
Bug: 391605373
Flag: com.android.settingslib.flags.new_status_bar_icons
Flag: com.android.systemui.status_bar_root_modernization
Change-Id: I4ffbdf7fcbca61576c460e0c78691881b0fbae96