broken implementation of overpass server switching

OsmModule has currently no access to preferences (Dagger is unable to inject into static variables)
this is nitial step toward fixing streetcomplete#1389 - preference selection is now working

app/src/main/java/de/westnordost/streetcomplete/Prefs.java

@@ -16,7 +16,9 @@ public class Prefs
 			AUTOSYNC = "autosync",
 			KEEP_SCREEN_ON = "display.keepScreenOn",
 			UNGLUE_HINT_TIMES_SHOWN = "unglueHint.shown",
-			THEME_SELECT = "theme.select";
+			THEME_SELECT = "theme.select",
+			OVERPASS_URL = "overpass_url";
+
 
 	// not shown anywhere directly
 	public static final String

app/src/main/java/de/westnordost/streetcomplete/data/OsmModule.java

@@ -1,9 +1,11 @@
 package de.westnordost.streetcomplete.data;
 
 import android.content.Context;
+import android.content.SharedPreferences;
 
 import java.io.File;
 
+import javax.inject.Inject;
 import javax.inject.Named;
 import javax.inject.Provider;
 import javax.inject.Singleton;
@@ -12,6 +14,7 @@
 import dagger.Provides;
 import de.westnordost.osmapi.user.UserDao;
 import de.westnordost.streetcomplete.ApplicationConstants;
+import de.westnordost.streetcomplete.Prefs;
 import de.westnordost.streetcomplete.data.osm.OsmQuestGiver;
 import de.westnordost.streetcomplete.data.osm.download.ElementGeometryCreator;
 import de.westnordost.streetcomplete.data.osm.download.OsmApiWayGeometrySource;
@@ -38,9 +41,12 @@
 @Module
 public class OsmModule
 {
+	@Inject
+	public static SharedPreferences prefs;
+
 	public static final String
 		OSM_API_URL = "https://api.openstreetmap.org/api/0.6/",
-		OVERPASS_API_URL = "https://overpass-api.de/api/",
+		OVERPASS_API_URL = prefs.getString(Prefs.OVERPASS_URL, "https://overpass-api.de/api/"),
 		ONEWAY_API_URL = "https://www.westnordost.de/streetcomplete/oneway-data-api/";
 
 

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

@@ -24,4 +24,13 @@
         <item>DARK</item>
     </string-array>
 
+    <string-array name="pref_entries_overpass_url_select" translatable="false">
+        <item>"https://overpass-api.de/api/"</item>
+        <item>"https://3.overpass.kumi.systems/api"</item>
+    </string-array>
+
+    <string-array name="pref_entryvalues_overpass_url_select" translatable="false">
+        <item>"https://overpass-api.de/api/"</item>
+        <item>"https://3.overpass.kumi.systems/api"</item>
+    </string-array>
 </resources>

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

@@ -649,6 +649,8 @@ Otherwise, you can download another keyboard in the app store. Popular keyboards
     <string name="theme_light">Light</string>
     <string name="theme_dark">Dark</string>
     <string name="theme_system_default">System default</string>
+    <string name="pref_title_overpass_url_select">Change Overpass server</string>
+    <string name="pref_title_overpass_url_info">may bypass censorship, for example in Russia</string>
     <string name="quest_accessible_for_pedestrians_separate_sidewalk_explanation">This street was tagged as having no sidewalk on either side. In the case that there is a sidewalk after all but it is displayed as a separate way, please answer \"sidewalk\".</string>
     <string name="action_open_location">Open location in another app</string>
     <string name="map_application_missing">No other map application installed</string>

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

@@ -104,6 +104,15 @@
             android:title="@string/pref_title_quests_restore_hidden"
             />
 
+        <ListPreference
+            android:key="overpass_url"
+            android:title="@string/pref_title_overpass_url_select"
+            android:summary="@string/pref_title_overpass_url_info"
+            android:defaultValue="https://overpass-api.de/api/"
+            android:entries="@array/pref_entries_overpass_url_select"
+            android:entryValues="@array/pref_entryvalues_overpass_url_select"
+            android:persistent="true"
+            />
     </PreferenceCategory>
 
 </PreferenceScreen>