Set request body to required to reflect the code base (elastic#27188)

Update API, Cluster Update Settings API and Put Index Template API didn't have the request body set to required in their spec, hence this commit updates the spec to align them with reality.

Author: olcbean

rest-api-spec/src/main/resources/rest-api-spec/api/cluster.put_settings.json

@@ -22,7 +22,8 @@
       }
     },
     "body": {
-      "description": "The settings to be updated. Can be either `transient` or `persistent` (survives cluster restart)."
+      "description": "The settings to be updated. Can be either `transient` or `persistent` (survives cluster restart).",
+      "required" : true
     }
   }
 }

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

@@ -7,8 +7,8 @@
       "paths": ["/_search/template", "/{index}/_search/template", "/{index}/{type}/_search/template"],
       "parts": {
         "index": {
-         "type" : "list",
-         "description" : "A comma-separated list of index names to search; use `_all` or empty string to perform the operation on all indices"
+          "type" : "list",
+          "description" : "A comma-separated list of index names to search; use `_all` or empty string to perform the operation on all indices"
         },
         "type": {
           "type" : "list",
@@ -17,18 +17,18 @@
       },
       "params" : {
         "ignore_unavailable": {
-            "type" : "boolean",
-            "description" : "Whether specified concrete indices should be ignored when unavailable (missing or closed)"
+          "type" : "boolean",
+          "description" : "Whether specified concrete indices should be ignored when unavailable (missing or closed)"
         },
         "allow_no_indices": {
-            "type" : "boolean",
-            "description" : "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
+          "type" : "boolean",
+          "description" : "Whether to ignore if a wildcard indices expression resolves into no concrete indices. (This includes `_all` string or when no indices have been specified)"
         },
         "expand_wildcards": {
-            "type" : "enum",
-            "options" : ["open","closed","none","all"],
-            "default" : "open",
-            "description" : "Whether to expand wildcard expression to concrete indices that are open, closed or both."
+          "type" : "enum",
+          "options" : ["open","closed","none","all"],
+          "default" : "open",
+          "description" : "Whether to expand wildcard expression to concrete indices that are open, closed or both."
         },
         "preference": {
           "type" : "string",
@@ -62,7 +62,8 @@
       }
     },
     "body": {
-      "description": "The search definition template and its params"
+      "description": "The search definition template and its params",
+      "required" : true
     }
   }
 }

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

@@ -88,7 +88,8 @@
       }
     },
     "body": {
-      "description": "The request definition using either `script` or partial `doc`"
+      "description": "The request definition requires either `script` or partial `doc`",
+      "required": true
     }
   }
 }