TunnelDetailFragment now restores state correctly after process death

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

app/src/main/java/com/wireguard/util/KeyedList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.util;
 
+import android.support.annotation.Nullable;
+
 import java.util.Collection;
 import java.util.List;
 
@@ -18,8 +20,10 @@ public interface KeyedList<K, E extends Keyed<? extends K>> extends List<E> {
 
     boolean containsKey(K key);
 
+    @Nullable
     E get(K key);
 
+    @Nullable
     E getLast(K key);
 
     int indexOfKey(K key);

app/src/main/java/com/wireguard/util/SortedKeyedList.java

@@ -5,6 +5,8 @@
 
 package com.wireguard.util;
 
+import android.support.annotation.Nullable;
+
 import java.util.Collection;
 import java.util.Comparator;
 import java.util.Set;
@@ -17,10 +19,12 @@ import java.util.Set;
 public interface SortedKeyedList<K, E extends Keyed<? extends K>> extends KeyedList<K, E> {
     Comparator<? super K> comparator();
 
+    @Nullable
     K firstKey();
 
     Set<K> keySet();
 
+    @Nullable
     K lastKey();
 
     Collection<E> values();