Indexed Templates : Add another rest test

This rest test indexes a template then uses it in search.

See elastic#5637

rest-api-spec/test/template/20_search.yaml

@@ -0,0 +1,38 @@
+---
+"Indexed Template query tests":
+
+  - do:
+      index:
+        index:  test
+        type:   testtype
+        id:     1
+        body:   { "text": "value1_foo" }
+  - do:
+      index:
+        index:  test
+        type:   testtype
+        id:     2
+        body:   { "text": "value2_foo value3_foo" }
+  - do:
+      indices.refresh: {}
+
+  - do:
+      indexed_template.create:
+        id: "1"
+        body: { "template": { "query": { "match" : { "text": "{{my_value}}" } }, "size": "{{my_size}}" } }
+  - match: { _id: "1" }
+
+  - do:
+      indices.refresh: {}
+
+
+  - do:
+      search_template:
+        body: { "template": { "id" : "1" }, "params" : { "my_value" : "value1_foo", "my_size" : 1 } }
+  - match: { hits.total: 1 }
+
+  - do:
+      search_template:
+        body: {  "id" : "1", "params" : { "my_value" : "value1_foo", "my_size" : 1 } }
+  - match: { hits.total: 1 }
+