[battery] color updates

- Allow for a separate color based on whether or not there are any
  glyphs to draw
- Update all of the colors to use a transparent bg fill
- Tweak the error state color
- Unified background colors between states
- Backgrounds are all white or black depending on the theme

Test: manual
Flag: com.android.settingslib.flags.new_status_bar_icons
Flag: com.android.systemui.status_bar_root_modernization
Bug: 400783306
Change-Id: Ic0ca9906f37755b521b15abf1569eac1f136ce6d