[bfcache] Filter out newly failing blink_web_tests

-virtual/webrtc-wpt-plan-b/external/wpt/webrtc/simulcast/h264.https.html
-external/wpt/webrtc/protocol/video-codecs.https.html
-virtual/webrtc-wpt-plan-b/external/wpt/webrtc/protocol/video-codecs.https.html
-external/wpt/webrtc/simulcast/h264.https.html

Also, rename
third_party/blink/web_tests/FlagExpectations/back-forward-cache to
third_party/blink/web_tests/FlagExpectations/enable-features=BackForwardCache
to match the name in test_suite_exceptions.pyl

Bug: 1103214
Change-Id: Ie6e65711c83c873d3ca5280c8a6d5b72e6daf796
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2287381Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Sreeja Kamishetty <sreejakshetty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#786472}

third_party/blink/web_tests/FlagExpectations/back-forward-cache → third_party/blink/web_tests/FlagExpectations/enable-features=BackForwardCache

@@ -7,3 +7,7 @@
 crbug.com/1010870 virtual/gpu/fast/canvas/color-space/canvas-createImageBitmap-e_srgb.html [ Failure ]
 crbug.com/1010870 virtual/gpu/fast/canvas/canvas-composite-alpha.html [ Failure ]
 crbug.com/1010870 virtual/gpu/fast/canvas/canvas-composite-text-alpha.html [ Failure ]
+crbug.com/1103214 virtual/webrtc-wpt-plan-b/external/wpt/webrtc/simulcast/h264.https.html [ Failure ]
+crbug.com/1103214 external/wpt/webrtc/protocol/video-codecs.https.html [ Failure ]
+crbug.com/1103214 virtual/webrtc-wpt-plan-b/external/wpt/webrtc/protocol/video-codecs.https.html [ Failure ]
+crbug.com/1103214 external/wpt/webrtc/simulcast/h264.https.html [ Failure ]
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