Fixed #27171 -- Added unicode_literals and coding preamble to all files in…

Fixed #27171 -- Added unicode_literals and coding preamble to all files in startapp template on Python 2.

django/conf/app_template/admin.py-tpl

-from django.contrib import admin
+{{ unicode_literals }}from django.contrib import admin
 
 # Register your models here.

django/conf/app_template/tests.py-tpl

-from django.test import TestCase
+{{ unicode_literals }}from django.test import TestCase
 
 # Create your tests here.

django/conf/app_template/views.py-tpl

-from django.shortcuts import render
+{{ unicode_literals }}from django.shortcuts import render
 
 # Create your views here.

django/core/management/templates.py

@@ -114,7 +114,8 @@ class TemplateCommand(BaseCommand):
             camel_case_name: camel_case_value,
             'docs_version': get_docs_version(),
             'django_version': django.__version__,
-            'unicode_literals': '' if six.PY3 else 'from __future__ import unicode_literals\n\n',
+            'unicode_literals': '' if six.PY3 else '# -*- coding: utf-8 -*-\n'
+                                                   'from __future__ import unicode_literals\n\n',
         }), autoescape=False)
 
         # Setup a stub settings environment for template rendering

tests/admin_scripts/tests.py

@@ -613,7 +613,7 @@ class DjangoAdminSettingsDirectory(AdminScriptTestCase):
         self.addCleanup(shutil.rmtree, app_path)
         self.assertNoOutput(err)
         self.assertTrue(os.path.exists(app_path))
-        unicode_literals_import = "from __future__ import unicode_literals\n"
+        unicode_literals_import = "# -*- coding: utf-8 -*-\nfrom __future__ import unicode_literals\n\n"
         with open(os.path.join(app_path, 'apps.py'), 'r') as f:
             content = f.read()
             self.assertIn("class SettingsTestConfig(AppConfig)", content)
@@ -624,6 +624,15 @@ class DjangoAdminSettingsDirectory(AdminScriptTestCase):
             with open(os.path.join(app_path, 'models.py'), 'r') as fp:
                 content = fp.read()
             self.assertIn(unicode_literals_import, content)
+            with open(os.path.join(app_path, 'views.py'), 'r') as fp:
+                content = fp.read()
+            self.assertIn(unicode_literals_import, content)
+            with open(os.path.join(app_path, 'admin.py'), 'r') as fp:
+                content = fp.read()
+            self.assertIn(unicode_literals_import, content)
+            with open(os.path.join(app_path, 'tests.py'), 'r') as fp:
+                content = fp.read()
+            self.assertIn(unicode_literals_import, content)
 
     def test_setup_environ_custom_template(self):
         "directory: startapp creates the correct directory with a custom template"