Switch back to using template located at _IMAGE_BUILDER because the previous change will break Go, Java and Node.
diff --git a/tools/interop_matrix/client_matrix.py b/tools/interop_matrix/client_matrix.py
index d2cd376..c7860f3 100644
--- a/tools/interop_matrix/client_matrix.py
+++ b/tools/interop_matrix/client_matrix.py
@@ -88,6 +88,15 @@
         'v1.6.6',
         'v1.7.2',    
     ],
+    'python': [
+        'v1.0.x',
+        'v1.1.4',
+        'v1.2.5',
+        'v1.3.9',
+        'v1.4.2',
+        'v1.6.6',
+        'v1.7.2',    
+    ],
     'node': [
         'v1.0.1',
         'v1.1.4',