This ensures that accidental usages of dart:io's
file API don't creep in over time.

This removes direct file access from within flutter_tools
in favor of using `package:file` via a `FileSystem` that's
accessed via the `ApplicationContext`.

This lays the groundwork for us to be able to easily swap
out the underlying file system when running Flutter tools,
which will be used to provide a record/replay file system,
analogous to what we have for process invocations.

* make app ids more unique

* in-line the uuid class

* making flutter run work with gradle

* locate android studio

* add test for settings

* review comments

* refactor the --resident run option into a separate file

* update daemon to run --resident apps

* re-plumbing daemon start

* send app logs

* update tests

* review changes

* fix test runner

* remove PackageMap.createGlobalInstance; rely on the ctor

* review comments

* show build progress; print app sizes

* add todo

* review comments

* remove unused import

* dissallow -release mode on emulators

* have the help text print the default mode

* rename service_protocol.dart to protocol_discovery.dart

* add a wrapper around the obs. protocol

* use json-rpc in run

* consolidate obs. code; implement flutter run --benchmark

* review comments

* avoid sending analytics on ci systems

* review comments

* use the new cache code to locate more artifacts

* add todo

* review comments