org--get-expected-indentation: Consider section parent type

* lisp/org.el (org--get-expected-indentation): Consider new :parent
structure when `org-element-at-point' returns parent section and
headline elements.

* testing/lisp/test-org.el (test-org/indent-region): Add test.

Fixes https://list.orgmode.org/87pmrupu0s.fsf@gmail.com/T/#t

lisp/org.el

@@ -19218,6 +19218,10 @@ ELEMENT."
       (contentsp
        (cl-case type
 	 ((diary-sexp footnote-definition) 0)
+         (section
+          (org--get-expected-indentation
+           (org-element-property :parent element)
+           t))
 	 ((headline inlinetask nil)
 	  (if (not org-adapt-indentation) 0
 	    (let ((level (org-current-level)))

testing/lisp/test-org.el

@@ -1168,6 +1168,13 @@
 		  (org-adapt-indentation nil))
 	      (org-indent-region (point) (point-max)))
 	    (buffer-string))))
+  ;; Indent property drawers according to `org-adapt-indentation'.
+  (let ((org-adapt-indentation 'headline-data))
+    (should
+     (equal "* H\n  :PROPERTIES:\n  :key:\n  :END:"
+            (org-test-with-temp-text "* H\n:PROPERTIES:\n:key:\n:END:"
+              (org-indent-region (point-min) (point-max))
+              (buffer-string)))))
   ;; Indent plain lists.
   (let ((org-adapt-indentation t))
     (should