Change label of file picker button.

app/src/main/res/values/strings.xml

@@ -11,7 +11,7 @@
     <string name="main_button_mood">Change Mood</string>
     <string name="main_button_beautiful">Beautiful</string>
 
-    <string name="file_transfer_button_pick_file">Select</string>
+    <string name="file_transfer_button_pick_file">Select file</string>
     <string name="file_transfer_button_start_transfer">Start</string>
     <string name="file_transfer_button_stop_transfer">Cancel</string>
     <string name="file_transfer_label_no_file_selected">No file selected</string>