Fix preference compat crash

Fixes #7018
// FREEBIE

build.gradle

@@ -85,7 +85,6 @@ dependencies {
     }
     provided 'com.squareup.dagger:dagger-compiler:1.2.2'
     compile 'com.amulyakhare:com.amulyakhare.textdrawable:1.0.1'
-    compile 'com.h6ah4i.android.compat:mulsellistprefcompat:1.0.0'
     compile 'com.google.zxing:core:3.2.1'
     compile ('com.davemorrissey.labs:subsampling-scale-image-view:3.6.0') {
         exclude group: 'com.android.support', module: 'support-annotations'
@@ -165,7 +164,6 @@ dependencyVerification {
         'com.squareup.dagger:dagger:789aca24537022e49f91fc6444078d9de8f1dd99e1bfb090f18491b186967883',
         'com.doomonafireball.betterpickers:library:132ecd685c95a99e7377c4e27bfadbb2d7ed0bea995944060cd62d4369fdaf3d',
         'com.amulyakhare:com.amulyakhare.textdrawable:54c92b5fba38cfd316a07e5a30528068f45ce8515a6890f1297df4c401af5dcb',
-        'com.h6ah4i.android.compat:mulsellistprefcompat:47167c5cb796de1a854788e9ff318358e36c8fb88123baaa6e38fb78511dfabe',
         'com.google.zxing:core:b4d82452e7a6bf6ec2698904b332431717ed8f9a850224f295aec89de80f2259',
         'com.davemorrissey.labs:subsampling-scale-image-view:550c5baa07e0bb4ff0a18b705e96d34436d22619248bd8c08c08c730b1f55cfe',
         'cn.carbswang.android:NumberPickerView:18b3c316d62c7c277978a8d4ed57a5b8f4e943762264960f579a8a549c756729',

res/xml/preferences_chats.xml

@@ -2,7 +2,7 @@
 
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
     <PreferenceCategory android:key="media_download" android:title="@string/preferences_chats__media_auto_download">
-        <com.h6ah4i.android.compat.preference.MultiSelectListPreferenceCompat
+        <MultiSelectListPreference
                 android:title="@string/preferences_chats__when_using_mobile_data"
                 android:key="pref_media_download_mobile"
                 android:defaultValue="@array/pref_media_download_mobile_data_default"
@@ -10,7 +10,7 @@
                 android:entries="@array/pref_media_download_values"
                 android:entryValues="@array/pref_media_download_entries" />
 
-        <com.h6ah4i.android.compat.preference.MultiSelectListPreferenceCompat
+        <MultiSelectListPreference
                 android:title="@string/preferences_chats__when_using_wifi"
                 android:key="pref_media_download_wifi"
                 android:defaultValue="@array/pref_media_download_wifi_default"
@@ -18,7 +18,7 @@
                 android:entries="@array/pref_media_download_values"
                 android:entryValues="@array/pref_media_download_entries" />
 
-        <com.h6ah4i.android.compat.preference.MultiSelectListPreferenceCompat
+        <MultiSelectListPreference
                 android:title="@string/preferences_chats__when_roaming"
                 android:key="pref_media_download_roaming"
                 android:defaultValue="@array/pref_media_download_roaming_default"

src/org/thoughtcrime/securesms/util/TextSecurePreferences.java

@@ -10,10 +10,9 @@ import android.support.annotation.ArrayRes;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.support.v4.app.NotificationCompat;
+import android.support.v4.content.SharedPreferencesCompat;
 import android.util.Log;
 
-import com.h6ah4i.android.compat.content.SharedPreferenceCompat;
-
 import org.thoughtcrime.securesms.R;
 import org.thoughtcrime.securesms.preferences.widgets.NotificationPrivacyPreference;
 
@@ -692,9 +691,7 @@ public class TextSecurePreferences {
   private static Set<String> getStringSetPreference(Context context, String key, Set<String> defaultValues) {
     final SharedPreferences prefs = PreferenceManager.getDefaultSharedPreferences(context);
     if (prefs.contains(key)) {
-      return SharedPreferenceCompat.getStringSet(PreferenceManager.getDefaultSharedPreferences(context),
-                                                 key,
-                                                 Collections.<String>emptySet());
+      return prefs.getStringSet(key, Collections.<String>emptySet());
     } else {
       return defaultValues;
     }