Bug 37319: Move mappings for 752ad (MARC21) and 210a/214a (UNIMARC) to pl index

In Bug 36578, some fields were added to the pl index, but somehow it
ended up in the other-control-number index. This aims to put fields
752ad (MARC21) and 210a/214a (UNIMARC) in the pl index.

Test plan:
----------
0. Have an installation with Elasticsearch and MARC 21 configuration.
1. Under  Administration > Search engine configuration (Elasticsearch)
   under the tab Bibliographic records check that you have 752ad in
   other-control-number search field.
2. Apply the patch, reindex with:
   sudo koha-elasticsearch --rebuild -r -b kohadev
3. Under  Administration > Search engine configuration (Elasticsearch)
   under the tab Bibliographic records check that you have 752ad in pl
   search field now.

Signed-off-by: Caroline Cyr La Rose <caroline.cyr-la-rose@inlibro.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
(cherry picked from commit a3f4c9ec8a)
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>

admin/searchengine/elasticsearch/mappings.yaml

@@ -3125,21 +3125,6 @@ biblios:
       marc_type: marc21
       sort: 1
       suggestible: ''
-    - facet: ''
-      marc_field: 752ad
-      marc_type: marc21
-      sort: 1
-      suggestible: ''
-    - facet: ''
-      marc_field: 210a
-      marc_type: unimarc
-      sort: 1
-      suggestible: ''
-    - facet: ''
-      marc_field: 214a
-      marc_type: unimarc
-      sort: 1
-      suggestible: ''
     opac: 1
     staff_client: 1
     type: ''
@@ -3194,6 +3179,21 @@ biblios:
       marc_type: marc21
       sort: 1
       suggestible: ''
+    - facet: ''
+      marc_field: 752ad
+      marc_type: marc21
+      sort: 1
+      suggestible: ''
+    - facet: ''
+      marc_field: 210a
+      marc_type: unimarc
+      sort: 1
+      suggestible: ''
+    - facet: ''
+      marc_field: 214a
+      marc_type: unimarc
+      sort: 1
+      suggestible: ''
     opac: 1
     staff_client: 1
     type: ''