This modifies the flutter update-packages and flutter update-packages --force-upgrade commands so that the many invocations of "dart pub get" in each repo project run in parallel instead of in series.
Our current top crasher is an unclear error when ProcessManager fails to resolve an executable path. To fix this, we'd like to being adjusting the process resolution logic and adding more instrumentation to track failures. In order to begin the process, the ProcessManager has been folded back into the flutter tool