Add proper scheduler_hint key to dev-ref

In the dev-ref, the hint key for volume create API
should be 'OS-SCH-HNT:scheduler_hints' but not 'scheduler_hints'.
Furthermore, it should be parallel with the key 'volume'.
To be more clear fix the example as well.

Change-Id: I999aebb0e53ebac5dc121ef1ccdc98f9d5ac816a

api-ref/v1/source/parameters.yaml

@@ -481,7 +481,7 @@ reserved_1:
   in: body
   required: true
   type: integer
-scheduler_hints:
+OS-SCH-HNT:scheduler_hints:
   description: |
     The dictionary of data to send to the scheduler.
   in: body

api-ref/v1/source/samples/volume-create-request.json

@@ -8,5 +8,11 @@
             "contents": "junk"
         },
         "availability_zone": "us-east1"
+    },
+    "OS-SCH-HNT:scheduler_hints": {
+        "same_host": [
+            "a0cf03a5-d921-4877-bb5c-86d26cf818e1",
+            "8c19174f-4220-44f0-824a-cd1eeef10287"
+        ]
     }
 }

api-ref/v1/source/volumes-v1-volumes.inc

@@ -91,7 +91,7 @@ Request
    - consistencygroup_id: consistencygroup_id
    - volume_type: volume_type
    - snapshot_id: snapshot_id
-   - scheduler_hints: scheduler_hints
+   - OS-SCH-HNT:scheduler_hints: OS-SCH-HNT:scheduler_hints
    - source_replica: source_replica
    - metadata: metadata
    - tenant_id: tenant_id

api-ref/v2/source/parameters.yaml

@@ -1236,7 +1236,7 @@ restore:
   in: body
   required: true
   type: object
-scheduler_hints:
+OS-SCH-HNT:scheduler_hints:
   description: |
     The dictionary of data to send to the scheduler.
   in: body

api-ref/v2/source/samples/volume-create-request.json

@@ -12,5 +12,11 @@
         "metadata": {},
         "source_replica": null,
         "consistencygroup_id": null
+    },
+    "OS-SCH-HNT:scheduler_hints": {
+        "same_host": [
+            "a0cf03a5-d921-4877-bb5c-86d26cf818e1",
+            "8c19174f-4220-44f0-824a-cd1eeef10287"
+        ]
     }
 }

api-ref/v2/source/volumes-v2-volumes.inc

@@ -167,7 +167,7 @@ Request
    - consistencygroup_id: consistencygroup_id
    - volume_type: volume_type
    - snapshot_id: snapshot_id
-   - scheduler_hints: scheduler_hints
+   - OS-SCH-HNT:scheduler_hints: OS-SCH-HNT:scheduler_hints
    - source_replica: source_replica
    - metadata: metadata
    - tenant_id: tenant_id