Use lowercase values for default_operator parameter (#136372) (#137109)

(cherry picked from commit 596b1ef)

# Conflicts:
#	rest-api-spec/src/main/resources/rest-api-spec/api/project.tags.json

Author: pquentin

rest-api-spec/src/main/resources/rest-api-spec/api/async_search.submit.json

@@ -78,10 +78,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {

rest-api-spec/src/main/resources/rest-api-spec/api/count.json

@@ -94,10 +94,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {

rest-api-spec/src/main/resources/rest-api-spec/api/delete_by_query.json

@@ -43,10 +43,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {

rest-api-spec/src/main/resources/rest-api-spec/api/explain.json

@@ -48,10 +48,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {

rest-api-spec/src/main/resources/rest-api-spec/api/indices.validate_query.json

@@ -82,10 +82,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {

rest-api-spec/src/main/resources/rest-api-spec/api/search.json

@@ -56,10 +56,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {

rest-api-spec/src/main/resources/rest-api-spec/api/update_by_query.json

@@ -43,10 +43,10 @@
       "default_operator": {
         "type": "enum",
         "options": [
-          "AND",
-          "OR"
+          "and",
+          "or"
         ],
-        "default": "OR",
+        "default": "or",
         "description": "The default operator for query string query (AND or OR)"
       },
       "df": {