Ues permission to protect DeepLinkHomepageActivity

DeepLinkHomepageActivity needs the permission
android.permission.LAUNCH_TWO_PANE_SETTINGS_DEEP_LINK
to limit the apps that can show Activity in Settings 2-pane.

The permission is of protectionLevel signature|preinstalled.
System grants the permission automatically to all the
preinstalled apps and the apps that signed with platform key.

Bug: 197048599
Test: build pass
Change-Id: I1c2de3c9cddae432c5ff6e5d6ad56959b8117f8b
diff --git a/AndroidManifest.xml b/AndroidManifest.xml
index d2a9c75..a34713d 100644
--- a/AndroidManifest.xml
+++ b/AndroidManifest.xml
@@ -178,6 +178,7 @@
         <activity-alias android:name="DeepLinkHomepageActivity"
                 android:label="@string/settings_label_launcher"
                 android:exported="true"
+                android:permission="android.permission.LAUNCH_TWO_PANE_SETTINGS_DEEP_LINK"
                 android:targetActivity=".homepage.SettingsHomepageActivity">
             <intent-filter>
                 <action android:name="android.settings.SETTINGS_LARGE_SCREEN_DEEP_LINK" />