Update 2.16 breaking changes documentation for Kibana init container renaming (#8497) (#8506)

* Update 2.16 breaking changes documentation for Kibana init container renaming.

Signed-off-by: Michael Montgomery <[email protected]>

* Recommended wording changes.

Co-authored-by: Michael Morello <[email protected]>

---------

Signed-off-by: Michael Montgomery <[email protected]>
Co-authored-by: Michael Morello <[email protected]>
(cherry picked from commit 3479731)

Author: naemono

docs/release-notes/2.16.0.asciidoc

@@ -4,7 +4,11 @@
 [[release-notes-2.16.0]]
 == {n} version 2.16.0
 
+[[breaking-2.16.0]]
+[float]
+=== Breaking changes
 
+* The initContainer for Kibana was renamed from `elastic-internal-init-config` to `elastic-internal-init` which could cause issues when a user has overridden the `podtemplate.spec.initContainers` with custom values. The recommendation is to link:https://www.elastic.co/guide/en/cloud-on-k8s/current/k8s-troubleshooting-methods.html#k8s-exclude-resource[exclude the Kibana resource from reconciliation] temporarily during upgrade of ECK and adjust the Kibana manifest to match the new initContainer name. After the ECK upgrade is complete remove the managed annotation from the Kibana manifest. {issue}8426[#8426]
 
 [[feature-2.16.0]]
 [float]