[ONOS-3648] Implement REST API for collecting system metrics

- Implement REST API for gathering system metrics
- Add unit test for REST API
- Add swagger doc for REST API

Change-Id: Iedd21a5f6ed14d595e4d35c1fa08270b48a5031e
diff --git a/apps/cpman/src/main/resources/definitions/SystemSpecsPost.json b/apps/cpman/src/main/resources/definitions/SystemSpecsPost.json
new file mode 100644
index 0000000..fc4fc16
--- /dev/null
+++ b/apps/cpman/src/main/resources/definitions/SystemSpecsPost.json
@@ -0,0 +1,31 @@
+{
+  "type": "object",
+  "required": [
+    "numOfCores",
+    "numOfCpus",
+    "cpuSpeed",
+    "totalMemory"
+  ],
+  "properties": {
+    "numOfCores": {
+      "type": "integer",
+      "format": "int64",
+      "example": "6"
+    },
+    "numOfCpus": {
+      "type": "integer",
+      "format": "int64",
+      "example": "2"
+    },
+    "cpuSpeed": {
+      "type": "integer",
+      "format": "int64",
+      "example": "2048"
+    },
+    "totalMemory": {
+      "type": "integer",
+      "format": "int64",
+      "example": "4096"
+    }
+  }
+}
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