Merge pull request rails#50752 from seanpdoyle/issue-49818-changelog

Re-word rails#49856 CHANGELOG entry [ci skip]

Author: byroot

actionview/CHANGELOG.md

@@ -11,7 +11,9 @@
 
     *Sean Doyle*
 
-*   Rename `ActionView::TestCase::Behavior::{Content,RenderedViewContent}`
+*   Rename `ActionView::TestCase::Behavior::Content` to `ActionView::TestCase::Behavior::RenderedViewContent`
+
+    Make `RenderedViewContent` inherit from `String`. Make private API with `:nodoc:`
 
     *Sean Doyle*