* Reland "Re-enable the Dart Development Service (DDS) (#64671)"
This reverts commit 2ae25cc2d7.
* Fix MDNS building Observatory URI with port 0 instead of forwarding the device port
* Added MDNS test
This change re-enables DDS and outputs the DDS URI in place of the VM
service URI on the console. If --disable-dds is not provided,
--host-vmservice-port will be used to determine the port for DDS rather
than the host port for the VM service, which will instead be randomly
chosen.
Also combines experiments into extraGenSnapshot/ExtraFrontEndOptions. Allows providing --no-sound-null-safety to allow out of order migration and running.
Fixes#51010
The test package differentiates between passing and not passing this
argument. A previous version had a bug that treated passing `0`
identically to not passing the argument, and the flutter test runner
relied on this bug by always passing a value and using a default of `0`.
- Remove the argument defaults throughout to make it clear that `null`
is a valid value and the default.
- Remove the argument defaulting on the argument parser.
- Update the wording of the usage for this argument, this will also be
updated on the `package:test` side.
