Add wallpaper default permissions

Change-Id: If43a594da31fbab9280ce45b049737f6c534b620
Reviewed-on: https://review.statixos.com/c/android_packages_apps_ThemePicker/+/5803
Reviewed-by: Anay Wadhera <anay1018@gmail.com>
Tested-by: Anay Wadhera <anay1018@gmail.com>
Reviewed-on: https://review.statixos.com/c/android_packages_apps_ThemePicker/+/7118

Android.bp

@@ -87,7 +87,10 @@ android_app {
 
     overrides: ["ThemePicker", "WallpaperPicker2", "WallpaperPicker"],
 
-    required: ["privapp_whitelist_com.android.wallpaper"],
+    required: [
+        "privapp_whitelist_com.android.wallpaper",
+        "default_permissions_com.android.wallpaper",
+    ],
 }
 
 prebuilt_etc {
@@ -97,3 +100,11 @@ prebuilt_etc {
     sub_dir: "permissions",
     filename_from_src: true,
 }
+
+prebuilt_etc_xml {
+    name: "default_permissions_com.android.wallpaper",
+    src: "default_permissions_com.android.wallpaper.xml",
+    system_ext_specific: true,
+    filename_from_src: true,
+    sub_dir: "default-permissions",
+}

default_permissions_com.android.wallpaper.xml

@@ -0,0 +1,37 @@
+<?xml version='1.0' encoding='utf-8' standalone='yes' ?>
+<!--
+     Copyright (C) 2019-2020 The LineageOS Project
+
+     Licensed under the Apache License, Version 2.0 (the "License");
+     you may not use this file except in compliance with the License.
+     You may obtain a copy of the License at
+
+          http://www.apache.org/licenses/LICENSE-2.0
+
+     Unless required by applicable law or agreed to in writing, software
+     distributed under the License is distributed on an "AS IS" BASIS,
+     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+     See the License for the specific language governing permissions and
+     limitations under the License.
+-->
+
+<!--
+    This file contains permissions to be granted by default. Default
+    permissions are granted to special platform components and to apps
+    that are approved to get default grants. The special components
+    are apps that are expected to work out-of-the-box as they provide
+    core use cases such as default dialer, default email, etc. These
+    grants are managed by the platform. The apps that are additionally
+    approved for default grants are ones that provide carrier specific
+    functionality, ones legally required at some location, ones providing
+    alternative disclosure and opt-out UI, ones providing highlight features
+    of a dedicated device, etc. This file contains only the latter exceptions.
+    Fixed permissions cannot be controlled by the user and need a special
+    approval. Typically these are to ensure either legally mandated functions
+    or the app is considered a part of the OS.
+-->
+<exceptions>
+    <exception package="com.android.wallpaper">
+        <permission name="android.permission.READ_EXTERNAL_STORAGE" fixed="false"/>
+    </exception>
+</exceptions>