Bug 1518724 [wpt PR 14756] - Update wpt metadata, a=testonly

wpt-pr: 14756
wpt-type: metadata

testing/web-platform/meta/storage/estimate-usage-details-service-workers.https.tentative.window.js.ini

@@ -0,0 +1,4 @@
+[estimate-usage-details-service-workers.https.tentative.window.html]
+  [estimate() shows usage increase after large value is stored]
+    expected: FAIL
+