The output for cr-buildbucket.cfg will now use a multiline indented
format for properties to make them easier to review and investigate
using git blame.

Bug: 1223219
Change-Id: Idd17689589a154991cfa8d4100cbe712f178d588
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/tools/depot_tools/+/3028746Reviewed-by: Vadim Shtayura <vadimsh@chromium.org>
Commit-Queue: Garrett Beaty <gbeaty@chromium.org>