MB-52431 Restore authType to pools/default/buckets/bucket-name response

XDCR on versions prior to 7.0 use the authType of the bucket to
determine whether or not the node is an elastic search target. This
change adds "sasl" for the authType in the bucket info results.

Change-Id: Ic9ff977f6caf157512e102070a3ed0e6aec0b6eb
Reviewed-on: https://review.couchbase.org/c/ns_server/+/175726
Well-Formed: Restriction Checker
Well-Formed: Build Bot <[email protected]>
Reviewed-by: Dave Finlay <[email protected]>
Reviewed-by: Artem Stemkovski <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: stevewatanabe

src/menelaus_web_buckets.erl

@@ -284,7 +284,10 @@ build_authType(BucketConfig) ->
         false ->
             [{authType, misc:expect_prop_value(auth_type, BucketConfig)}];
         true ->
-            []
+            %% Needed by XDCR on versions prior to 7.0. This must remain
+            %% until there are no supported pre-7.0 versions that can
+            %% replicate to us.
+            [{authType, sasl}]
     end.
 
 build_sasl_password(BucketConfig) ->