DevTools: Temporarily disable harImporter.js test

Original change that introduced change to NetworkRequest object:
https://chromium-review.googlesource.com/c/chromium/src/+/2142145

DevTools browser_protocol.pdl is getting updated, but is failing
this test, so need to disable test temporarily till it gets checked in:
https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/2220495

Bug: 1066579
Change-Id: Ie2a39211993646f67487de2646f6befd0e8af987
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2220809
Reviewed-by: Tim van der Lippe <tvanderlippe@chromium.org>
Reviewed-by: Robert Paveza <Rob.Paveza@microsoft.com>
Commit-Queue: Anubha Mathur <anubmat@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#773234}

third_party/blink/web_tests/TestExpectations

@@ -5797,6 +5797,7 @@ crbug.com/1067533 [ Mac10.10 ] external/wpt/shape-detection/idlharness.https.any
 
 # Temporarily disabled for landing changes to DevTools frontend
 crbug.com/1066595 http/tests/devtools/tracing/timeline-network/timeline-network-resource.js [ Pass Failure ]
+crbug.com/1066579 http/tests/devtools/har-importer.js [ Pass Failure ]
 
 # Flaky test, happens only on Mac 10.13.
 # The "timeout" was detected by the wpt-importer bot.