AW: remove WebViewSslTests from the filter

These tests already work with the NetworkService enabled. The confusion
was because the test was previously broken (and a chromium change
exposed this), but the test has since been fixed (http://aosp/878513). I
ran these tests on an up-to-date copy of Android master to verify.

Bug: 933814
Test: build/android/adb_system_webview_command_line --enable-features=NetworkService,NetworkServiceInProcess
Test: cd /path/to/android/master/
Test: atest CtsWebkitTestCases:WebViewSslTest#testSecureServerRequiringClientCertDoesCancelRequest
Test: atest CtsWebkitTestCases:WebViewSslTest#testSecureServerRequestingClientCertDoesNotCancelRequest
Change-Id: Icfc11d9e164e05e4a2dafcb99206cb340cce336a
Reviewed-on: https://chromium-review.googlesource.com/c/1487956Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Commit-Queue: Nate Fischer <ntfschr@chromium.org>
Auto-Submit: Nate Fischer <ntfschr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636263}

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

@@ -23,8 +23,6 @@
 -android.webkit.cts.WebChromeClientTest.testOnJsBeforeUnloadIsCalled
 -android.webkit.cts.WebViewClientTest.testOnReceivedError
 -android.webkit.cts.WebViewClientTest.testShouldOverrideUrlLoading
--android.webkit.cts.WebViewSslTest.testSecureServerRequestingClientCertDoesNotCancelRequest
--android.webkit.cts.WebViewSslTest.testSecureServerRequiringClientCertDoesCancelRequest
 -android.webkit.cts.WebViewTest.testSetDownloadListener
 -com.android.cts.webkit.WebViewDeviceSideStartupTest.testCookieManagerBlockingUiThread