Fix test_package for Windows

templates/command/new/device/test_package/conanfile.py

@@ -14,4 +14,7 @@ class {{package}}TestConan(ConanFile):
 
     def test(self):
         if can_run(self):
-            self.run("{{executable}} 2>&1 | grep \"^usage\"", env="conanrun")
+            if self.settings.os == "Windows":
+                self.run("{{executable}} 2>&1 | findstr \"usage\"", env="conanrun")
+            else:
+                self.run("{{executable}} 2>&1 | grep \"usage\"", env="conanrun")