Battery status/bar: Fix Colors:

Battery status (symbol and text):
- Battery level for changing color from custom color to red is now at 15%, (global warning level),
  (was 14%)

Battery status (circle):
- Battery level for changing color from custom color to red is now at 15%, (global warning level)
  (fixes the issue battery status text turns to black instead of red, too)
- Some code cleanup

Battery bar:
- Using value "RED" from Color class instead value "ffff3300"
  (to match with battery status)
- Fix charging state detection