add RBD Provisioner Addon (#3667) (#3668)

Based on the CephFS Provisioner Addon, the following changes have been made:
 - Upstream v2.1.1-k8s1.11
 - Configurable Provisioner replicas

roles/kubernetes-apps/external_provisioner/rbd_provisioner/templates/deploy-rbd-provisioner.yml.j2

@@ -0,0 +1,42 @@
+---
+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: rbd-provisioner
+  namespace: {{ rbd_provisioner_namespace }}
+  labels:
+    app: rbd-provisioner
+    version: {{ rbd_provisioner_image_tag }}
+spec:
+  replicas: {{ rbd_provisioner_replicas }}
+  strategy:
+    type: Recreate
+  selector:
+    matchLabels:
+      app: rbd-provisioner
+      version: {{ rbd_provisioner_image_tag }}
+  template:
+    metadata:
+      labels:
+        app: rbd-provisioner
+        version: {{ rbd_provisioner_image_tag }}
+    spec:
+{% if kube_version is version('v1.11.1', '>=') %}
+      priorityClassName: {% if rbd_provisioner_namespace == 'kube-system' %}system-cluster-critical{% else %}k8s-cluster-critical{% endif %}{{''}}
+{% endif %}
+      serviceAccount: rbd-provisioner
+      containers:
+        - name: rbd-provisioner
+          image: {{ rbd_provisioner_image_repo }}:{{ rbd_provisioner_image_tag }}
+          imagePullPolicy: {{ k8s_image_pull_policy }}
+          env:
+            - name: PROVISIONER_NAME
+              value: ceph.com/rbd
+            - name: POD_NAME
+              valueFrom:
+                fieldRef:
+                  fieldPath: metadata.name
+          command:
+            - "/usr/local/bin/rbd-provisioner"
+          args:
+            - "-id=${POD_NAME}"