Create an informative issue (See each section, incomplete templates/issues won't be triaged)

Using the current documentation as a model, please complete the issue template. 

Note: Doc team updates the current version and the two previous versions (n-2). For earlier versions, we will address only high-priority, customer-reported issues for releases in support.

Prerequisite: Start with what we have

Always look at the current documentation to describe the change that is needed. Use the source or portal link for Step 4:

 - Use the Customer Portal: https://access.redhat.com/documentation/en-us/red_hat_advanced_cluster_management_for_kubernetes

 - Use the GitHub link to find the staged docs in the repository: https://github.com/stolostron/rhacm-docs 

Describe the changes in the doc and link to your dev story

Provide info for the following steps:

1. - [ ] Mandatory Add the required version to the Fix version/s field.

2. - [ ] Mandatory Choose the type of documentation change.

      - [ ] New topic in an existing section or new section
      - [X] Update to an existing topic

3. - [X] Mandatory for GA content:
            
       - [ ] Add steps and/or other important conceptual information here: 
       
            
       - [ ] Add Required access level for the user to complete the task here:
       

       - [ ] Add verification at the end of the task, how does the user verify success (a command to run or a result to see?)
     
     
       - [X] Add link to dev story here:

https://issues.redhat.com/browse/ACM-10528

4. - [X] Mandatory for bugs: What is the diff? Clearly define what the problem is, what the change is, and link to the current documentation:

Add a new known issue with workaround for app LC to ACM 2.10/2.9/2.8 release note

Also publish a KCS as discussed in the SoS

Here is the draft:

Known issue:

leases.coordination.k8s.io api is required by app addon component, but it is missing in OCP V3.11.  The Kubernetes Lease API is introduced in k8s version 1.14, while k8s v1.11 is bundled by OCP v3.11

Workaround:

manually apply the following lease api CRD to the OCP v3.11 managed cluster.

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
  name: leases.coordination.k8s.io
spec:
  group: coordination.k8s.io
  names:
    kind: Lease
    listKind: LeaseList
    plural: leases
    singular: lease
    shortNames:
    - ls
  scope: Namespaced
  versions:
  - name: v1
    served: true    storage: true    schema:
      openAPIV3Schema:
        description: Lease defines a lease concept.
        type: object
        properties:
          apiVersion:
            type: string
          kind:
            type: string
          metadata:
            type: object
          spec:
            type: object
            properties:
              acquireTime:
                format: date-time
                type: string
              holderIdentity:
                type: string
              leaseDurationSeconds:
                format: int64
                type: integer
              leaseTransitions:
                format: int64
                type: integer
              renewTime:
                format: date-time
                type: string
            required:
            - holderIdentity
            - leaseDurationSeconds
            - renewTime
        required:
        - kind
        - metadata
        - spec
  additionalPrinterColumns:
  - JSONPath: .metadata.creationTimestamp
    name: Age
    type: date
  subresources:
    status: {}