Being able to see the output of the GL pipeline is useful for debugging. For
example, when we previously saw flakiness it would have been useful to be able
to tell quickly whether the output looked wrong without needing to run a
transformation to the end then inspect the output file, and when working on
support for HDR editing it's useful to be able to do manual testing on devices
that don't support HDR encoding (but do support decoding/processing it with
GL).
Also change the progress indicator to be linear as this looks better in the
demo app when shown next to the debug preview.
PiperOrigin-RevId: 414999491
174120a7cf