Bubbles styling: Update colors to use new theme things

- Bubble expanded view arrow is now based on backgroundColorFloating
- Bubble overflow expanded view also uses backgroundColorFloating
- Bubble overflow button uses colorAccentPrimary for the circle
  & a dark accent color for the '+' shape
- Manage menu uses colorSurface, had to rename the file bc sysui
  has a file with same name but different colour which was clobbering
  ours

Test: make a bubble & observe UI in light and dark mode, check
      the arrow in the expanded view, the overflow button & expanded
      state, and tapping on the manage menu
Bug: 183658029
Bug: 183658858
Change-Id: Iab5e5536036a8eaecd1c547e5dcfc9d4e77fe5d4