Network Service Sheriffing: Fix some layout tests expectation

https://chromium-review.googlesource.com/c/chromium/src/+/1318750
The above CL changed the layout test expected file for the following
two tests:
http/tests/inspector-protocol/network/raw-headers-for-protected-document.js
http/tests/inspector-protocol/network/security-info-on-response.js
and these two tests fail in the Mojo Linux and Mojo Windows trybots:
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mojo%20Linux?numbuilds=200
https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mojo%20Windows?numbuilds=200

This CL adds an expectation of failure for these two tests to:
//third_party/WebKit/LayoutTests/FlagExpectations/enable-features=NetworkService

Bug: 898306
Change-Id: I63fb64fe5531c55dbcb06e9642aee22411ca5342
Reviewed-on: https://chromium-review.googlesource.com/c/1345432
Commit-Queue: Jun Cai <juncai@chromium.org>
Reviewed-by: Łukasz Anforowicz <lukasza@chromium.org>
Cr-Commit-Position: refs/heads/master@{#610155}

third_party/WebKit/LayoutTests/FlagExpectations/enable-features=NetworkService

@@ -24,3 +24,6 @@ crbug.com/849670 http/tests/devtools/service-workers/service-worker-v8-cache.js
 # because content_shell does not add the about: handler. With network service
 # enabled this fails in both content_shell and chrome.
 Bug(none) http/tests/misc/redirect-to-about-blank.html [ Timeout ]
+
+crbug.com/898306 http/tests/inspector-protocol/network/raw-headers-for-protected-document.js [ Failure ]
+crbug.com/898306 http/tests/inspector-protocol/network/security-info-on-response.js [ Failure ]