Fix conversation menu colors.

res/layout/conversation_activity.xml

@@ -9,7 +9,8 @@
         android:id="@+id/toolbar"
         android:layout_width="match_parent"
         android:layout_height="?attr/actionBarSize"
-        android:theme="@style/TextSecure.LightActionBar"
+        android:background="?attr/conversation_list_toolbar_background"
+        android:theme="?attr/actionBarStyle"
         app:contentInsetStartWithNavigation="0dp"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"