This fixes the issue we had with shared/diamond depedencies. This also matches
more closely how DDK is invoked internally and externally.
While the change to use `--dart-sdk-summary` is not necessary, this brings the
API closer to how it is used elsewhere. It should be cleaned up in the future to
reuse the `--input-summary` flag instead.
Change-Id: Iec3695b5541ffaf7f5762a3d77f071a596237da1
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/119723
Reviewed-by: Nicholas Shahan <nshahan@google.com>
Commit-Queue: Sigmund Cherem <sigmund@google.com>