Delete existing system resource during enrollment (Wind-River#427)

During the enrollment, it is possible that the system resource name
applied during enrollment deffers from the existing one. To prevent
this problem, this commit checks the existing system resources and
delete them before applying new system resource.

Test plan:
Passed -  successfully finish the subcloud enrollment with this
change. The system resource applied during the enrollment deffers from
the existing system resource. Verify the system resource can be insync
and reconciled after enrollment.

Signed-off-by: Yuxing Jiang <Yuxing.Jiang@windriver.com>
(cherry picked from commit d62d60d)

docs/playbooks/wind-river-cloud-platform-deployment-manager.yaml

@@ -429,13 +429,37 @@
           failed_when: false
           register: scope_principal
 
-        - name: Fail if system subcloud enrollment finalized but have principal in scope
-          fail:
-            msg:
-              "Cannot apply principal scope on enrolled subcloud before unlock."
-          when:
-            - scope_principal.stdout_lines | length > 0
-            - subcloud_enrollment
+        - name: Pre-check and process for subcloud enrollment
+          block:
+          - name: Fail if system subcloud enrollment but have principal in scope
+            fail:
+              msg: "Principal scope cannot used in subcloud enrollment."
+            when: scope_principal.stdout_lines | length > 0
+
+          - name: Retrieve all system resource names
+            command: kubectl -n deployment get systems -o jsonpath='{.items[*].metadata.name}'
+            environment:
+              KUBECONFIG: "/etc/kubernetes/admin.conf"
+            register: system_resource_names
+
+          - name: Parse the system resource names into a list
+            set_fact:
+              system_resources: "{{ system_resource_names.stdout.split() }}"
+            when: system_resource_names.stdout | length > 0
+
+          - name: Debug the list of system resource names
+            debug:
+              msg: "System resources to be deleted: {{ system_resources }}"
+            when: system_resources is defined
+
+          - name: Delete all system resources
+            command: |
+              kubectl -n deployment delete system {{ item }}
+            loop: "{{ system_resources }}"
+            environment:
+              KUBECONFIG: "/etc/kubernetes/admin.conf"
+            when: system_resources is defined and system_resources | length > 0
+          when: subcloud_enrollment
 
         # Check if there is any strategy-related alarm
         - name: Check if a VIM strategy is in progress