fix(logstash): Adjust role for ECS compatibility

'ecs_compatibility' is now on by default, therefore Logstash indices are
created with the naming pattern "ecs-logstash-*" when data streams are
disabled ('data_stream => false').

setup/roles/logstash_writer.json

@@ -8,7 +8,8 @@
     {
       "names": [
         "logs-generic-default",
-        "logstash-*"
+        "logstash-*",
+        "ecs-logstash-*"
       ],
       "privileges": [
         "write",
@@ -20,7 +21,8 @@
     },
     {
       "names": [
-        "logstash"
+        "logstash",
+        "ecs-logstash"
       ],
       "privileges": [
         "write",