Fix analyzer issues (#3863)

* Make infos fatal when analyzing packages
* Fix import ordering for updated analysis
diff --git a/script/tool/lib/src/analyze_command.dart b/script/tool/lib/src/analyze_command.dart
index e17400f..61be5f9 100644
--- a/script/tool/lib/src/analyze_command.dart
+++ b/script/tool/lib/src/analyze_command.dart
@@ -70,7 +70,8 @@
     final List<String> failingPackages = <String>[];
     await for (final Directory package in getPlugins()) {
       final int exitCode = await processRunner.runAndStream(
-          'dart', <String>['analyze'], workingDir: package);
+          'dart', <String>['analyze', '--fatal-infos'],
+          workingDir: package);
       if (exitCode != 0) {
         failingPackages.add(p.basename(package.path));
       }
diff --git a/script/tool/lib/src/version_check_command.dart b/script/tool/lib/src/version_check_command.dart
index 39fecc0..db69f4e 100644
--- a/script/tool/lib/src/version_check_command.dart
+++ b/script/tool/lib/src/version_check_command.dart
@@ -4,9 +4,9 @@
 
 import 'dart:async';
 
-import 'package:meta/meta.dart';
 import 'package:file/file.dart';
 import 'package:git/git.dart';
+import 'package:meta/meta.dart';
 import 'package:pub_semver/pub_semver.dart';
 import 'package:pubspec_parse/pubspec_parse.dart';
 
diff --git a/script/tool/test/analyze_command_test.dart b/script/tool/test/analyze_command_test.dart
index ac6b8ee..11acb59 100644
--- a/script/tool/test/analyze_command_test.dart
+++ b/script/tool/test/analyze_command_test.dart
@@ -46,8 +46,10 @@
               'flutter', const <String>['packages', 'get'], plugin1Dir.path),
           ProcessCall(
               'flutter', const <String>['packages', 'get'], plugin2Dir.path),
-          ProcessCall('dart', const <String>['analyze'], plugin1Dir.path),
-          ProcessCall('dart', const <String>['analyze'], plugin2Dir.path),
+          ProcessCall('dart', const <String>['analyze', '--fatal-infos'],
+              plugin1Dir.path),
+          ProcessCall('dart', const <String>['analyze', '--fatal-infos'],
+              plugin2Dir.path),
         ]));
   });
 
@@ -86,7 +88,8 @@
           orderedEquals(<ProcessCall>[
             ProcessCall(
                 'flutter', const <String>['packages', 'get'], pluginDir.path),
-            ProcessCall('dart', const <String>['analyze'], pluginDir.path),
+            ProcessCall('dart', const <String>['analyze', '--fatal-infos'],
+                pluginDir.path),
           ]));
     });
 
diff --git a/script/tool/test/publish_plugin_command_test.dart b/script/tool/test/publish_plugin_command_test.dart
index 9966e59..02d6d81 100644
--- a/script/tool/test/publish_plugin_command_test.dart
+++ b/script/tool/test/publish_plugin_command_test.dart
@@ -9,8 +9,8 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/local.dart';
-import 'package:flutter_plugin_tools/src/publish_plugin_command.dart';
 import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/publish_plugin_command.dart';
 import 'package:git/git.dart';
 import 'package:matcher/matcher.dart';
 import 'package:mockito/mockito.dart';
diff --git a/script/tool/test/util.dart b/script/tool/test/util.dart
index e926d60..25b248b 100644
--- a/script/tool/test/util.dart
+++ b/script/tool/test/util.dart
@@ -9,9 +9,9 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:file/memory.dart';
+import 'package:flutter_plugin_tools/src/common.dart';
 import 'package:meta/meta.dart';
 import 'package:platform/platform.dart';
-import 'package:flutter_plugin_tools/src/common.dart';
 import 'package:quiver/collection.dart';
 
 // TODO(stuartmorgan): Eliminate this in favor of setting up a clean filesystem
diff --git a/script/tool/test/version_check_test.dart b/script/tool/test/version_check_test.dart
index 0434831..ea1a82a 100644
--- a/script/tool/test/version_check_test.dart
+++ b/script/tool/test/version_check_test.dart
@@ -8,11 +8,11 @@
 import 'package:args/command_runner.dart';
 import 'package:file/file.dart';
 import 'package:flutter_plugin_tools/src/common.dart';
+import 'package:flutter_plugin_tools/src/version_check_command.dart';
 import 'package:git/git.dart';
 import 'package:mockito/mockito.dart';
-import 'package:test/test.dart';
-import 'package:flutter_plugin_tools/src/version_check_command.dart';
 import 'package:pub_semver/pub_semver.dart';
+import 'package:test/test.dart';
 import 'util.dart';
 
 void testAllowedVersion(