Missing/Invalid Default Value (Group 4) (#3454)

## Why make this change?

Parent issue #3466 
Closes #3366 — `runtime.rest.enabled` has no `default` in the JSON
schema
Closes #3367 — `runtime.graphql.enabled` has no `default` in the JSON
schema

These schema properties were missing an explicit `default` value.

5 of 7 Group 4 issues (#3378–#3382) were already fixed in PR #3417 as
Group 2 overlaps.

## What is this change?

Adds `"default": true` to the `enabled` property under both
`runtime.rest` and `runtime.graphql` in `schemas/dab.draft.schema.json`.
This matches the C# runtime behavior where both REST and GraphQL are
enabled by default.

## How was this tested?

Schema-only metadata change — no runtime behavior affected. Validated
that the schema still passes JSON Schema draft-07 validation.

## Sample Request(s)

NA

Author: souvikghosh04

schemas/dab.draft.schema.json

@@ -212,7 +212,8 @@
             },
             "enabled": {
               "$ref": "#/$defs/boolean-or-string",
-              "description": "Allow enabling/disabling REST requests for all entities."
+              "description": "Allow enabling/disabling REST requests for all entities.",
+              "default": true
             },
             "request-body-strict": {
               "$ref": "#/$defs/boolean-or-string",
@@ -237,7 +238,8 @@
             },
             "enabled": {
               "$ref": "#/$defs/boolean-or-string",
-              "description": "Allow enabling/disabling GraphQL requests for all entities."
+              "description": "Allow enabling/disabling GraphQL requests for all entities.",
+              "default": true
             },
             "depth-limit": {
               "type": [ "integer", "null" ],