[License] Enable flutter_style_todos lint

engine/src/flutter/tools/licenses/analysis_options.yaml

@@ -39,6 +39,7 @@ linter:
     - constant_identifier_names
     - control_flow_in_finally
     - empty_constructor_bodies
+    - flutter_style_todos
     - implementation_imports
     - library_names
     - library_prefixes

engine/src/flutter/tools/licenses/lib/filesystem.dart

@@ -275,8 +275,10 @@ FileType identifyFile(String name, Reader reader) {
     return FileType.binary; // GIF89a
   if (matchesSignature(bytes, <int>[0x64, 0x65, 0x78, 0x0A, 0x30, 0x33, 0x35, 0x00]))
     return FileType.binary; // Dalvik Executable
-  if (matchesSignature(bytes, <int>[0x21, 0x3C, 0x61, 0x72, 0x63, 0x68, 0x3E, 0x0A]))
-    return FileType.binary; // Unix archiver (ar) // TODO(ianh): implement .ar parser
+  if (matchesSignature(bytes, <int>[0x21, 0x3C, 0x61, 0x72, 0x63, 0x68, 0x3E, 0x0A])) {
+    // TODO(ianh): implement .ar parser, https://github.com/flutter/flutter/issues/25633
+    return FileType.binary; // Unix archiver (ar)
+  }
   if (matchesSignature(bytes, <int>[0x89, 0x50, 0x4E, 0x47, 0x0D, 0x0A, 0x1A, 0x0a]))
     return FileType.binary; // PNG
   if (matchesSignature(bytes, <int>[0x58, 0x50, 0x43, 0x4f, 0x4d, 0x0a, 0x54, 0x79, 0x70, 0x65, 0x4c, 0x69, 0x62, 0x0d, 0x0a, 0x1a]))