Replace runtime push-requests expert setting with a compile-time configuration

This partially reverts commit c2d9749105

* This feature let repos automatically install / uninstall apps.
* It does not make sense to have as a user-facing option.
* Change this to a compile-time option to allow whitelabel builds to
  easily enable this while securely keeping it disabled for everyone else
  who doesn't need it.
* For more background, see:
  https://gitlab.com/fdroid/fdroidclient/-/merge_requests/1063#note_702867355
  https://gitlab.com/fdroid/fdroid-website/-/merge_requests/721

Change-Id: Id5113816accaade2813b1ef053bf57afd5144ddb

app/src/main/java/org/fdroid/fdroid/IndexUpdater.java

@@ -26,6 +26,7 @@ package org.fdroid.fdroid;
 import android.content.ContentResolver;
 import android.content.ContentValues;
 import android.content.Context;
+import android.content.res.Resources.NotFoundException;
 import android.content.pm.PackageInfo;
 import android.text.TextUtils;
 import android.util.Log;
@@ -453,12 +454,16 @@ public class IndexUpdater {
      * Server index XML can include optional {@code install} and {@code uninstall}
      * requests.  This processes those requests, figuring out whether the client
      * should always accept, prompt the user, or ignore those requests on a
-     * per repo basis.  There is also a global preference as a failsafe.
+     * per repo basis.  There is also a compile-time option as a failsafe.
      *
-     * @see Preferences#allowPushRequests()
      */
     void processRepoPushRequests(List<RepoPushRequest> requestEntries) {
-        if (!Preferences.get().allowPushRequests()) {
+        try {
+            if (!context.getResources().getBoolean(R.bool.config_allowPushRequests)) {
+                return;
+            }
+        } catch (NotFoundException e) {
+            Utils.debugLog(TAG, "allowPushRequests configuration not found, defaulting to false");
             return;
         }
         for (RepoPushRequest repoPushRequest : requestEntries) {

app/src/main/java/org/fdroid/fdroid/Preferences.java

@@ -121,7 +121,6 @@ public final class Preferences implements SharedPreferences.OnSharedPreferenceCh
     public static final String PREF_HIDE_ON_LONG_PRESS_SEARCH = "hideOnLongPressSearch";
     public static final String PREF_HIDE_ALL_NOTIFICATIONS = "hideAllNotifications";
     public static final String PREF_SEND_VERSION_AND_UUID_TO_SERVERS = "sendVersionAndUUIDToServers";
-    public static final String PREF_ALLOW_PUSH_REQUESTS = "allowPushRequests";
 
     public static final int OVER_NETWORK_NEVER = 0;
     public static final int OVER_NETWORK_ON_DEMAND = 1;
@@ -572,16 +571,6 @@ public final class Preferences implements SharedPreferences.OnSharedPreferenceCh
         return preferences.getBoolean(PREF_SEND_VERSION_AND_UUID_TO_SERVERS, IGNORED_B);
     }
 
-    /**
-     * Whether push requests are globally enabled or disabled.
-     *
-     * @see org.fdroid.fdroid.data.RepoPushRequest
-     * @see IndexUpdater#processRepoPushRequests(List)
-     */
-    public boolean allowPushRequests() {
-        return preferences.getBoolean(PREF_ALLOW_PUSH_REQUESTS, IGNORED_B);
-    }
-
     /**
      * This is cached as it is called several times inside app list adapters.
      * Providing it here means the shared preferences file only needs to be

app/src/main/res/values/config.xml

@@ -0,0 +1,19 @@
+<!--
+~ Copyright (C) 2021 The Calyx Institute
+~
+~ 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.
+-->
+
+<resources>
+	<bool name="config_allowPushRequests">false</bool>
+</resources>

app/src/main/res/values/strings.xml

@@ -47,9 +47,6 @@
         downloading, takes affect next app restart.</string>
     <string name="force_old_index">Force old index format</string>
     <string name="force_old_index_summary">In case there are bugs or compatibility issues, use the XML app index</string>
-    <string name="allow_push_requests">Allow repos to install/uninstall apps</string>
-    <string name="allow_push_requests_summary">Repo metadata can include "push requests" to install or uninstall apps
-    </string>
     <string name="other">Other</string>
 
     <string name="update_interval">Automatic update interval</string>

app/src/main/res/xml/preferences.xml

@@ -202,12 +202,6 @@
             android:key="sendVersionAndUUIDToServers"
             android:summary="@string/send_version_and_uuid_summary"
             android:title="@string/send_version_and_uuid" />
-        <CheckBoxPreference
-            android:defaultValue="false"
-            android:dependency="expert"
-            android:key="allowPushRequests"
-            android:summary="@string/allow_push_requests_summary"
-            android:title="@string/allow_push_requests" />
         <CheckBoxPreference
             android:defaultValue="false"
             android:dependency="expert"