Remove need for single_item when calling GetGSNamesWithWait

BUG=chromium:286453
TEST=Ran it with new devserver code.

Change-Id: I7cb235f16723b7720bdfc4c7019d2d59f34892c7
Previous-Reviewed-on: https://chromium-review.googlesource.com/168474
(cherry picked from commit 728736163fe2ec04c8eb93b27bf4070e5dad1f05)
Reviewed-on: https://chromium-review.googlesource.com/174416
Reviewed-by: Chris Sosa <sosa@chromium.org>
Tested-by: Chris Sosa <sosa@chromium.org>
diff --git a/site_utils/autoupdate/test_image.py b/site_utils/autoupdate/test_image.py
index e39cded..eb5e7a8 100644
--- a/site_utils/autoupdate/test_image.py
+++ b/site_utils/autoupdate/test_image.py
@@ -36,6 +36,10 @@
     pass
 
 
+class NotSingleItem(Exception):
+    """Raised when we want a single item but got multiple."""
+
+
 def get_default_archive_url(board, build_version):
     """Returns the default archive_url for the given board and build_version .
 
@@ -82,11 +86,13 @@
         logging.debug('Searching for pattern %s from url %s', pattern,
                       archive_url)
         uri_list = gsutil_util.GetGSNamesWithWait(
-                pattern, archive_url, err_str=__name__, single_item=single,
-                timeout=1)
+                pattern, archive_url, err_str=__name__, timeout=1)
         # Convert to the format our clients expect (full archive path).
         if uri_list:
-            return ['/'.join([archive_url, u]) for u in uri_list]
+            if not single or (single and len(uri_list) == 1):
+                return ['/'.join([archive_url, u]) for u in uri_list]
+            else:
+                raise NotSingleItem()
 
         return []
     except gsutil_util.PatternNotSpecific as e:
@@ -110,9 +116,9 @@
 
     """
     if delta:
-        pattern = '.*_delta_.*'
+        pattern = '*_delta_*'
     else:
-        pattern = '.*_full_.*'
+        pattern = '*_full_*'
 
     payload_uri_list = gs_ls(pattern, archive_url, single)
     if not payload_uri_list: