chore(Upgrade guide): removed verbiage on button aria-disabled (patternfly#4494)

* chore(Upgrade guide): removed verbiage on button aria-disabled

* Updated verbiage for ariadisabled being conditionally rendered

* Feedback from Erin

Author: thatblindgeye

packages/documentation-site/patternfly-docs/content/get-started/upgrade.md

@@ -172,8 +172,10 @@ If you have previously implemented any breakpoint logic based on a pixel value,
 #### Button
 
 1. *Cannot find aria-disabled*
-    - **Cause:** We changed the `isDisabled` prop to assign a value for `disabled`, but none for `aria-disabled`. 
-    - **Fix:** Remove tests that look for `aria-disabled` in buttons.
+    - **Cause:** We changed button's `isDisabled` prop to assign a value for `disabled`, but none for `aria-disabled`. The exception to this is when the `component` prop is passed anything other than "button" as a value. Additionally, `aria-disabled` will now only render when true.
+    - **Fix:** Remove tests that look for `aria-disabled` in buttons when the expectation is either:
+      - For `aria-disabled` to be false.
+      - For `aria-disabled` to match `isDisabled` when `component="button"`.
 
 1. *Cannot find button attributes when using byText*
     - **Cause:** We added a wrapping `div` around button text. The RTL `byText` query returns that wrapper instead of the button element itself, where button's attributes live. 
@@ -199,4 +201,4 @@ Reach out to us on Slack
 Ask a question in GitHub Discussions
 </Button>
 
-**Note:** If you use a custom solution to replicate PatternFly styling (without using PatternFly components), then your product will need to be re-skinned. This may be a large undertaking, so we encourage you to get help from the PatternFly team.
+**Note:** If you use a custom solution to replicate PatternFly styling (without using PatternFly components), then your product will need to be re-skinned. This may be a large undertaking, so we encourage you to get help from the PatternFly team.