Make 'Disappears' in message details translatable

Fixes #5755
Closes #5756

// FREEBIE

res/layout/message_details_header.xml

@@ -84,7 +84,8 @@
 
                 <TextView android:layout_width="wrap_content"
                           android:layout_height="wrap_content"
-                          android:text="Disappears"
+                          android:text="@string/message_details_header__disappears"
+                          android:gravity="right"
                           android:textStyle="bold"/>
 
                 <TextView android:id="@+id/expires_in"

res/values/strings.xml

@@ -924,6 +924,7 @@
     <string name="message_details_header__issues_need_your_attention">Some issues need your attention.</string>
     <string name="message_details_header__sent">Sent</string>
     <string name="message_details_header__received">Received</string>
+    <string name="message_details_header__disappears">Disappears</string>
     <string name="message_details_header__via">Via</string>
     <string name="message_details_header__to">To:</string>
     <string name="message_details_header__from">From:</string>