Add provided ServiceAccount documentation to drafts (#1232)

Signed-off-by: Tayler Geiger <[email protected]>

Author: trgeiger

docs/drafts/provided-serviceaccount.md

@@ -0,0 +1,31 @@
+# Provided ServiceAccount for ClusterExtension Installation and Management
+
+Adhering to OLM v1's "Secure by Default" tenet, OLM v1 does not have the permissions
+necessary to install content. This follows the least privilege principle and reduces
+the chance of a [confused deputy attack](https://en.wikipedia.org/wiki/Confused_deputy_problem).
+Instead, users must explicitly specify a ServiceAccount that will be used to perform the
+installation and management of a specific ClusterExtension. The ServiceAccount is specified
+in the ClusterExtension manifest as follows:
+
+```yaml
+apiVersion: olm.operatorframework.io/v1alpha1
+kind: ClusterExtension
+metadata:
+  name: argocd
+spec:
+  source:
+    sourceType: Catalog
+    catalog:
+      packageName: argocd-operator
+      version: 0.6.0
+  install:
+    namespace: argocd
+    serviceAccount:
+      name: argocd-installer
+```
+
+The ServiceAccount must be configured with the RBAC permissions required by the ClusterExtension.
+If the permissions do not meet the minimum requirements, installation will fail. If no ServiceAccount
+is provided in the ClusterExtension manifest, then the manifest will be rejected.
+
+//TODO: Add link to documentation on determining least privileges required for the ServiceAccount