Change text on "done" to say "return"

Fixes b/6468243 While adding chips to the To field display label "Return" instead of "Done"

Change-Id: I42f9a845c553f0aa01971c5b3221ce5d0504c810
diff --git a/chips/res/values/strings.xml b/chips/res/values/strings.xml
index 369a6cb..f67d440 100644
--- a/chips/res/values/strings.xml
+++ b/chips/res/values/strings.xml
@@ -26,4 +26,7 @@
     <!-- Text displayed when the user long presses on a chip to copy the recipient's phone number.
          [CHAR LIMIT=200] -->
     <string name="copy_number">Copy phone number</string>
+    <!-- Text displayed in the enter key slot when the recipientedittextview has focus.
+         [CHAR LIMIT=12] -->
+    <string name="done">Return</string>
 </resources>