Include AppShell when scanning application for shells/commands.

Refs #12153

src/Console/CommandScanner.php

@@ -64,13 +64,13 @@ class CommandScanner
             App::path('Shell')[0],
             $appNamespace . '\Shell\\',
             '',
-            ['app']
+            []
         );
         $appCommands = $this->scanDir(
             App::path('Command')[0],
             $appNamespace . '\Command\\',
             '',
-            ['app']
+            []
         );
 
         return array_merge($appShells, $appCommands);

tests/TestCase/Console/CommandCollectionTest.php

@@ -204,11 +204,13 @@ class CommandCollectionTest extends TestCase
         $collection = new CommandCollection();
         $collection->addMany($collection->autoDiscover());
 
+        $this->assertTrue($collection->has('app'));
         $this->assertTrue($collection->has('demo'));
         $this->assertTrue($collection->has('i18m'));
         $this->assertTrue($collection->has('sample'));
         $this->assertTrue($collection->has('testing_dispatch'));
 
+        $this->assertSame('TestApp\Shell\AppShell', $collection->get('app'));
         $this->assertSame('TestApp\Command\DemoCommand', $collection->get('demo'));
         $this->assertSame('TestApp\Shell\I18mShell', $collection->get('i18m'));
         $this->assertSame('TestApp\Shell\SampleShell', $collection->get('sample'));