[DevicePage] Turn Display and Keyboard tests into suites

Allows the addition of further display and keyboard tests needed to
test out deep linking.

Bug: 1084154
Change-Id: I9b66ee94364403fa977bdb3b14c29d748114a555
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2372814Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Commit-Queue: Daniel Classon <dclasson@google.com>
Cr-Commit-Position: refs/heads/master@{#801195}

chrome/test/data/webui/settings/chromeos/os_settings_browsertest.js

@@ -502,7 +502,7 @@ TEST_F('OSSettingsAppManagementReducersTest', 'AllJsTests', () => {
   mocha.run();
 });
 
-// Tests for the Device page.
+// Tests for the Bluetooth page.
 // eslint-disable-next-line no-var
 var OSSettingsBluetoothPageTest = class extends OSSettingsBrowserTest {
   /** @override */