Revert "[release] Temporarily disable gerrit for merge tools."

This reverts commit 58ff145e.

Reason for revert: the bug in git-numberer has been fixed and deployed.

Original change's description:
> [release] Temporarily disable gerrit for merge tools.
> 
> BUG=chromium:698845
> NOTRY=true
> TBR=hablich@chromium.org,tandrii@chromium.org
> 
> Change-Id: I970c984c5e9bd23ca3d951d13243d107fc2a2e3f
> Reviewed-on: https://chromium-review.googlesource.com/451280
> Reviewed-by: Michael Achenbach <machenbach@chromium.org>
> Reviewed-by: Michael Hablich <hablich@chromium.org>
> Commit-Queue: Michael Hablich <hablich@chromium.org>
> Commit-Queue: Michael Achenbach <machenbach@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#43646}

R=machenbach@chromium.org,hablich@chromium.org
# Not skipping CQ checks because original CL landed > 1 day ago.
BUG=chromium:698845

Change-Id: I34b12a36c21a2d7a46eb67bce0536298a0582dd5
Reviewed-on: https://chromium-review.googlesource.com/455799Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#43840}

tools/release/common_includes.py

@@ -820,7 +820,7 @@ class ScriptsBase(object):
                         help="File to write results summary to.")
     parser.add_argument("-r", "--reviewer", default="",
                         help="The account name to be used for reviews.")
-    parser.add_argument("--rietveld", default=True, action="store_true",
+    parser.add_argument("--rietveld", default=False, action="store_true",
                         help="Whether to use rietveld instead of gerrit.")
     parser.add_argument("-s", "--step",
         help="Specify the step where to start work. Default: 0.",

tools/release/test_scripts.py

@@ -1271,7 +1271,7 @@ LOG=N
       Cmd("git commit -aF \"%s\"" % TEST_CONFIG["COMMITMSG_FILE"], ""),
       RL("reviewer@chromium.org"),  # V8 reviewer.
       Cmd("git cl upload --send-mail -r \"reviewer@chromium.org\" "
-          "--bypass-hooks --cc \"ulan@chromium.org\"", ""),
+          "--bypass-hooks --cc \"ulan@chromium.org\" --gerrit", ""),
       Cmd("git checkout -f %s" % TEST_CONFIG["BRANCHNAME"], ""),
       RL("LGTM"),  # Enter LGTM for V8 CL.
       Cmd("git cl presubmit", "Presubmit successfull\n"),
@@ -1653,7 +1653,7 @@ NOTREECHECKS=true
       Cmd("git commit -aF \"%s\"" % TEST_CONFIG["COMMITMSG_FILE"], ""),
       RL("reviewer@chromium.org"),  # V8 reviewer.
       Cmd("git cl upload --send-mail -r \"reviewer@chromium.org\" "
-          "--bypass-hooks --cc \"ulan@chromium.org\"", ""),
+          "--bypass-hooks --cc \"ulan@chromium.org\" --gerrit", ""),
       Cmd("git checkout -f %s" % TEST_CONFIG["BRANCHNAME"], ""),
       RL("LGTM"),  # Enter LGTM for V8 CL.
       Cmd("git cl presubmit", "Presubmit successfull\n"),