Update webview network service filter

This test was recently re-enabled in http://crrev.com/c/1286031.
The bot has been failing since then.

TBR=jam@chromium.org

Bug: 893563
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I190f142001a0334ad16ba839d0835c58fb95a361
Reviewed-on: https://chromium-review.googlesource.com/c/1289151Reviewed-by: Clark DuVall <cduvall@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Clark DuVall <cduvall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#600827}

testing/buildbot/filters/mojo.fyi.network_webview_instrumentation_test_apk.filter

@@ -18,6 +18,7 @@
 -org.chromium.android_webview.test.AwContentsClientAutoLoginTest.testAutoLoginWithNullAccount
 
 # https://crbug.com/893563
+-org.chromium.android_webview.test.AwContentsClientFullScreenTest.testExitFullscreenEndsIfAppInvokesCallbackFromOnHideCustomView
 -org.chromium.android_webview.test.AwContentsClientFullScreenTest.testFullscreenNotSupported_video
 -org.chromium.android_webview.test.AwContentsClientFullScreenTest.testFullscreenNotSupported_videoInsideDiv
 -org.chromium.android_webview.test.AwContentsClientFullScreenTest.testOnShowCustomViewAndPlayWithHtmlControl_video