[m141] Pretty print jobs.json

Cherry-pick of https://review.skia.org/1056297

Change-Id: I63b4651201c22501eca8f627e32e00d76ee38df3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/1056377
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
2 files changed