Bazel: default edition setting to cre

The CRE is a good default as it's available everywhere, including
GitHub, and is expected to be more minimal than the other
enterprise editions.

Change-Id: I41e8b294b349a5cd86e9848d44b6e3a22d70b5c5

Author: Synss

bazel/cmk/edition/BUILD

@@ -4,7 +4,7 @@ package(default_visibility = ["//visibility:public"])
 
 string_flag(
     name = "edition",
-    build_setting_default = "UNSET",
+    build_setting_default = "cre",
     values = [
         "cre",
         "cce",