[Battery] Improve contrasts

Light theme (dark icon) fill colors are now lighter to improve the
contrast ratio to any foreground attribution (percent or icon).
Similarly with dark them (light icons), but the opposite.

Test: go/battery-2024-companion
Test: manual
Fixes: 331969915
Flag: ACONFIG com.android.settingslib.flags.new_status_bar_icons TEAMFOOD
Change-Id: I9341c68d4a7c944bed8d203ed4f7ca794cb1a144