Switch off creating a keystone admin endpoint by default

With the depending patch, the endpoint will still be created for
heat tests, so we can turn it off for everyone else.

Depends-On: https://review.opendev.org/c/openstack/openstacksdk/+/777343
Change-Id: I0dc7d6cedd07e942b9f23b26a785b386aff41fbc

Author: jharbott

lib/keystone

@@ -123,7 +123,7 @@ KEYSTONE_PASSWORD_HASH_ROUNDS=${KEYSTONE_PASSWORD_HASH_ROUNDS:-4}
 KEYSTONE_ENABLE_CACHE=${KEYSTONE_ENABLE_CACHE:-True}
 
 # Whether to create a keystone admin endpoint for legacy applications
-KEYSTONE_ADMIN_ENDPOINT=$(trueorfalse True KEYSTONE_ADMIN_ENDPOINT)
+KEYSTONE_ADMIN_ENDPOINT=$(trueorfalse False KEYSTONE_ADMIN_ENDPOINT)
 
 # Functions
 # ---------