Flatten thread: localize missing string

Bug: twpowertools:157
Change-Id: Iee619a271bf5ef85531071cfdad17d766fe5e8ab
diff --git a/src/lit-locales/source/ar.xlf b/src/lit-locales/source/ar.xlf
index a029342..a200acb 100644
--- a/src/lit-locales/source/ar.xlf
+++ b/src/lit-locales/source/ar.xlf
@@ -14,6 +14,9 @@
   <source>More</source>
   <note from="lit-localize">Button to expand the quote message (used in the flatten threads feature).</note>
 </trans-unit>
+<trans-unit id="s6b0ed0c74667d28c">
+  <source><x id="0" equiv-text="${authorName}"/> said:</source>
+</trans-unit>
 </body>
 </file>
 </xliff>