Fix flutter_tools BUILD.gn dependencies (#9187)

This package now depends on collection and quiver. The package level
dependencies in the BUILD.gn file should match the list of dependencies
in the pubspec.yaml file for the Fuchsia build to function.

packages/flutter_tools/BUILD.gn

@@ -16,6 +16,7 @@ dart_tool("flutter_tools") {
     "//dart/third_party/pkg/linter",
     "//third_party/dart-pkg/pub/archive",
     "//third_party/dart-pkg/pub/args",
+    "//third_party/dart-pkg/pub/collection",
     "//third_party/dart-pkg/pub/coverage",
     "//third_party/dart-pkg/pub/crypto",
     "//third_party/dart-pkg/pub/file",
@@ -29,6 +30,7 @@ dart_tool("flutter_tools") {
     "//third_party/dart-pkg/pub/path",
     "//third_party/dart-pkg/pub/platform",
     "//third_party/dart-pkg/pub/process",
+    "//third_party/dart-pkg/pub/quiver",
     "//third_party/dart-pkg/pub/stack_trace",
     "//third_party/dart-pkg/pub/test",
     "//third_party/dart-pkg/pub/usage",