Add test that the lint works for any expression, not just variables

Author: oprypin

lib/src/rules/no_literal_bool_comparisons.dart

@@ -17,7 +17,7 @@ From [Effective Dart](https://dart.dev/guides/language/effective-dart/usage#dont
 
 **DON'T** use `true` or `false` in equality operations.
 
-This lint applies only if the variable is of a non-nullable `bool` type.
+This lint applies only if the expression is of a non-nullable `bool` type.
 
 **BAD:**
 ```dart

test_data/rules/no_literal_bool_comparisons.dart

@@ -20,6 +20,9 @@ void foo() {
   {
     print('oh');
   }
+
+  print((x && f) != true); // LINT
+  print(x && (f != true)); // LINT
 }
 
 void bar(bool x, bool? y) {