Add fixes for more lints

pkg/analysis_server/lib/src/services/correction/fix.dart

Index: pkg/analysis_server/lib/src/services/correction/fix.dart
diff --git a/pkg/analysis_server/lib/src/services/correction/fix.dart b/pkg/analysis_server/lib/src/services/correction/fix.dart
index 4ad9804107286b5094e6c411964f0153bf02317f..2d5a7aa5fb02dd2298dc3df79b1ad3072f097daf 100644
--- a/pkg/analysis_server/lib/src/services/correction/fix.dart
+++ b/pkg/analysis_server/lib/src/services/correction/fix.dart
@@ -228,6 +228,8 @@ class DartFixKind {
       "Use effective integer division ~/");
   static const USE_EQ_EQ_NULL =
       const FixKind('USE_EQ_EQ_NULL', 50, "Use == null instead of 'is Null'");
+  static const USE_IS_NOT_EMPTY = const FixKind(
+      'USE_NOT_EMPTY', 50, "Use x.isNotEmpty instead of '!x.isEmpty'");
   static const USE_NOT_EQ_NULL =
       const FixKind('USE_NOT_EQ_NULL', 50, "Use != null instead of 'is! Null'");
 }