Replace all the icons in OSD with large symbolic assets

This is long overdue but the scaled up 16x16 symbolics in all of the on-screen popups, e.g. volume brightness, etc. really are visually heavy and the icon design tricks done to accommodate things like aliasing at 16x16 are not suited to being seen at a scaled up size.

I'd like to replace all instances where there is a scaled symbolic icon with an appropriately sized symbolic asset and ship those with the shell.

This is the short list of assets that are needed:

• volume icons
• mic level icons
• airplane mode
• wifi icon (when airplane mode is turned off)
• display brightness
• keyboard brightness
• notifications empty state (this isn't a symbolic currently but it can be)

Feel free to add to this list.