Add "DIFF_LINES_OF_CONTEXT: 1" to fix format issue

Update codereview.settings file to workaround git cl format
issue based on change in this https://crrev.com/c/1864309

Bug: angleproject:4003
Change-Id: I4352800535465e8cac85aa6148c21d28c099ca5a
Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/1866275
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>

codereview.settings

@@ -3,3 +3,4 @@ CODE_REVIEW_SERVER: https://chromium-review.googlesource.com
 GERRIT_HOST: True
 TRYSERVER_GERRIT_URL: https://chromium-review.googlesource.com
 GERRIT_SQUASH_UPLOADS: False
+DIFF_LINES_OF_CONTEXT: 1