Pin all dependencies ONCE AND FOR ALL (#12210)

* Pin all dependencies ONCE AND FOR ALL

This replaces the secret `flutter update-packages --upgrade` with a destructive `flutter update-packages --force-upgrade` that actually goes and pins every dependency and transitive dependency in every flutter package to the same version.

* Add comments.
diff --git a/examples/platform_channel_swift/pubspec.yaml b/examples/platform_channel_swift/pubspec.yaml
index 100eccd..c608f9e 100644
--- a/examples/platform_channel_swift/pubspec.yaml
+++ b/examples/platform_channel_swift/pubspec.yaml
@@ -8,7 +8,62 @@
   flutter_test:
     sdk: flutter
   flutter_driver:
-    path: ../../packages/flutter_driver
+    sdk: flutter
+
+  args: 0.13.7 # TRANSITIVE DEPENDENCY
+  async: 1.13.3 # TRANSITIVE DEPENDENCY
+  barback: 0.15.2+11 # TRANSITIVE DEPENDENCY
+  boolean_selector: 1.0.2 # TRANSITIVE DEPENDENCY
+  charcode: 1.1.1 # TRANSITIVE DEPENDENCY
+  cli_util: 0.1.2+1 # TRANSITIVE DEPENDENCY
+  collection: 1.14.3 # TRANSITIVE DEPENDENCY
+  convert: 2.0.1 # TRANSITIVE DEPENDENCY
+  crypto: 2.0.2+1 # TRANSITIVE DEPENDENCY
+  csslib: 0.14.1 # TRANSITIVE DEPENDENCY
+  dart_style: 1.0.8 # TRANSITIVE DEPENDENCY
+  file: 2.3.4 # TRANSITIVE DEPENDENCY
+  glob: 1.1.3 # TRANSITIVE DEPENDENCY
+  html: 0.13.2 # TRANSITIVE DEPENDENCY
+  http: 0.11.3+14 # TRANSITIVE DEPENDENCY
+  http_multi_server: 2.0.3 # TRANSITIVE DEPENDENCY
+  http_parser: 3.1.1 # TRANSITIVE DEPENDENCY
+  intl: 0.15.1 # TRANSITIVE DEPENDENCY
+  intl_translation: 0.15.0 # TRANSITIVE DEPENDENCY
+  isolate: 1.1.0 # TRANSITIVE DEPENDENCY
+  js: 0.6.1 # TRANSITIVE DEPENDENCY
+  json_rpc_2: 2.0.4 # TRANSITIVE DEPENDENCY
+  logging: 0.11.3+1 # TRANSITIVE DEPENDENCY
+  matcher: 0.12.1+4 # TRANSITIVE DEPENDENCY
+  meta: 1.1.1 # TRANSITIVE DEPENDENCY
+  mime: 0.9.3 # TRANSITIVE DEPENDENCY
+  node_preamble: 1.4.0 # TRANSITIVE DEPENDENCY
+  package_config: 1.0.2 # TRANSITIVE DEPENDENCY
+  package_resolver: 1.0.2 # TRANSITIVE DEPENDENCY
+  path: 1.4.2 # TRANSITIVE DEPENDENCY
+  petitparser: 1.6.1 # TRANSITIVE DEPENDENCY
+  plugin: 0.2.0+1 # TRANSITIVE DEPENDENCY
+  pool: 1.3.2 # TRANSITIVE DEPENDENCY
+  pub_semver: 1.3.2 # TRANSITIVE DEPENDENCY
+  quiver: 0.24.0 # TRANSITIVE DEPENDENCY
+  shelf: 0.7.0 # TRANSITIVE DEPENDENCY
+  shelf_packages_handler: 1.0.3 # TRANSITIVE DEPENDENCY
+  shelf_static: 0.2.5 # TRANSITIVE DEPENDENCY
+  shelf_web_socket: 0.2.1 # TRANSITIVE DEPENDENCY
+  source_map_stack_trace: 1.1.4 # TRANSITIVE DEPENDENCY
+  source_maps: 0.10.4 # TRANSITIVE DEPENDENCY
+  source_span: 1.4.0 # TRANSITIVE DEPENDENCY
+  stack_trace: 1.8.2 # TRANSITIVE DEPENDENCY
+  stream_channel: 1.6.1 # TRANSITIVE DEPENDENCY
+  string_scanner: 1.0.2 # TRANSITIVE DEPENDENCY
+  term_glyph: 1.0.0 # TRANSITIVE DEPENDENCY
+  test: 0.12.24+2 # TRANSITIVE DEPENDENCY
+  typed_data: 1.1.4 # TRANSITIVE DEPENDENCY
+  utf: 0.9.0+3 # TRANSITIVE DEPENDENCY
+  vector_math: 2.0.5 # TRANSITIVE DEPENDENCY
+  vm_service_client: 0.2.2+4 # TRANSITIVE DEPENDENCY
+  watcher: 0.9.7+4 # TRANSITIVE DEPENDENCY
+  web_socket_channel: 1.0.5 # TRANSITIVE DEPENDENCY
+  yaml: 2.1.12 # TRANSITIVE DEPENDENCY
 
 flutter:
   uses-material-design: true