This was causing flaky failures when initializing DDS as it was invoking
the getVM RPC which in turn sometimes accessed the script_uri after it
had been freed.
Change-Id: I4454b6fa2da3ad6767938ed12b1013223a667af7
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/155740
Commit-Queue: Ben Konyi <bkonyi@google.com>
Reviewed-by: Siva Annamalai <asiva@google.com>