Bug 1462778 [wpt PR 11022] - Update wpt metadata, a=testonly

wpt-pr: 11022
wpt-type: metadata

testing/web-platform/meta/feature-policy/experimental-features/document-stream-insertion.tentative.html.ini

@@ -0,0 +1,13 @@
+[document-stream-insertion.tentative.html]
+  [Verify 'document.open' is blocked when the feature is disabled.]
+    expected: FAIL
+
+  [Verify 'document.close' is blocked when the feature is disabled.]
+    expected: FAIL
+
+  [Verify 'document.write' is blocked when the feature is disabled.]
+    expected: FAIL
+
+  [Verify 'document.writeln' is blocked when the feature is disabled.]
+    expected: FAIL
+