Hide volume boost options when not supported

app/src/main/java/de/danoeh/antennapod/preferences/VolumeAdaptationPreference.java

@@ -0,0 +1,27 @@
+package de.danoeh.antennapod.preferences;
+
+import android.content.Context;
+import android.util.AttributeSet;
+
+import java.util.Arrays;
+
+import de.danoeh.antennapod.model.feed.VolumeAdaptionSetting;
+
+public class VolumeAdaptationPreference extends MaterialListPreference {
+    public VolumeAdaptationPreference(Context context) {
+        super(context);
+    }
+
+    public VolumeAdaptationPreference(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    @Override
+    public CharSequence[] getEntries() {
+        if (VolumeAdaptionSetting.BOOST_SUPPORTED) {
+            return super.getEntries();
+        } else {
+            return Arrays.copyOfRange(super.getEntries(), 0, 3);
+        }
+    }
+}

app/src/main/res/xml/feed_settings.xml

@@ -48,7 +48,7 @@
         android:summary="@string/global_default"
         android:title="@string/auto_delete_label" />
 
-    <de.danoeh.antennapod.preferences.MaterialListPreference
+    <de.danoeh.antennapod.preferences.VolumeAdaptationPreference
         android:defaultValue="off"
         android:entries="@array/spnVolumeAdaptationItems"
         android:entryValues="@array/spnVolumeAdaptationValues"