[Fuchsia] Un-filter URLRequestTestHTTP.Redirect* tests.

These tests were flakily hanging, with unsufficient diagnostic output
for us to diagnose the issue. Now that we have per-Run() timeouts we
can re-enable these tests to get diagnostic call-stacks when they hang.

Bug: 913037
Change-Id: I5ef11d59e78304ac7182e3953d7a693f7ec502e4
Reviewed-on: https://chromium-review.googlesource.com/c/1406139
Commit-Queue: Wez <wez@chromium.org>
Reviewed-by: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622071}

testing/buildbot/filters/fuchsia.net_unittests.filter

@@ -18,9 +18,6 @@
 -URLRequestQuicTest.CancelPushIfCached_*
 -URLRequestQuicTest.DoNotCancelPushIfNotFoundInCache
 
-# Flaky hangs, https://crbug.com/913037.
--URLRequestTestHTTP.Redirect30*
-
 # SocketPosix::IsConnected has a different behavior on Fuchsia.
 # https://crbug.com/887587.
 -TCPSocketTest.BeforeConnectCallback