Small code changes as part of moving the framework SDK forward to a 2.0 dev version.

* update APK path in devicelab tests

* add missing transitive dependency on archive

* use path used by flutter tools

* Change some of the dev/devicelab tests to support testing against local engine.

We can already configure flutter tools to use local engine by setting
FLUTTER_ENGINE environment variable. However when this variable is set
this also requires setting --local-engine to specify which flavor of
engine to use.

This change changes tests in dev/devicelab to pass a sensible default for
--local-engine, e.g. when testing hot reload on Android we pass android_debug
and when testing release AOT build for IOS we pass ios_release.

* Fix analysis issues

* Update utils.dart

This fills out the following matrix:

App: `flutter create` default app, Complex Layout, and Gallery.
Platforms: Linux/Android, Mac/iOS, Windows/Android
Build modes: full release, aot blobs, debug
Dart: normal, 2.0 preview

It also renames all the tests that used "build" to mean compilation
build to use "compile" instead, so that it's much clearer on the
dashboard.

Also, mark some flaky tests that are no longer flaky as not flaky.
Also, remove uses of call() since that's probably going to go away at
some point.

This adds --preview-dart-2 flag that enables use of Dart 2.0 Frontend in Flutter tools.

Enable plugin infra for both iOS and Android post-#9791.

Brings hello_world and flutter_gallery Android code in line with the
corresponding iOS code.

Eliminates Gallery-specific hardcoding of app package and activity name
in the test.

Fixes breakage introduced with 1dc2d4eb
due to main activity class now being MainActivity.

Remove checked in .lock, remove checked in cocoapods scripts in xcode project, let the automated test run pod install specifically for this test

Broken by 89af5ec8.

* Rename platform_services to platform_channel

* rename in README

* renamed tests

* update modules.xml

* Add start-up test for flutter_view sample

* add reportMetrics flag to startup test

* rewording in manifest.yaml

This remove a very brittle aspect of flutter drive, whereby it would
assume a known port instead of explicitly finding out what it was.

Fixes #7692 and hopefully fixes the devicelab tests.

* fix flutter watch benchmark

Syncs https://github.com/flutter/cocoon/commit/d2d7950ecd2c72421d75d9b5d54805cc554e92a8

* Split Android/iOS impl behind a unified interface

Syncs https://github.com/flutter/cocoon/commit/db87e10fa54317115479d0b85280c7e5eed08ff7

* Switch from pub get to flutter packages get

Syncs https://github.com/flutter/cocoon/commit/b378005cbbc5330058d5240a2970ca477c2c9722

* "silent" option in test runner; fix analysis errors;