Use case

Some time ago I implemented configurable pixel formats for the embedder API software rendering backend: flutter/engine#26995

Though what I didn't think about is that the enum values I chose there might be a bit too general, i.e. there's maybe some programs that use kRGBA8888 as identifiers somewhere. (Incidentally, that's the case for my own embedder)

Proposal

Rename the values of the FlutterSoftwarePixelFormat enum and properly namespace them, to avoid name collisions:

kGray8 --> kGray8_FlutterSoftwarePixelFormat
kRGB565 --> kRGB565_FlutterSoftwarePixelFormat
...