Add oppressive language presubmit

BUG=b:162024466
TEST=try to upload a CL with a blocked term

Change-Id: I9cbe44033ce5ba3298f7797cf7de73f25fe01b30
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/sis-updater/+/2666374
Reviewed-by: Joe Tessler <jrt@chromium.org>
Commit-Queue: Harry Cutts <hcutts@chromium.org>
Tested-by: Harry Cutts <hcutts@chromium.org>
Auto-Submit: Harry Cutts <hcutts@chromium.org>
diff --git a/unblocked_terms.txt b/unblocked_terms.txt
new file mode 100644
index 0000000..161f69a
--- /dev/null
+++ b/unblocked_terms.txt
@@ -0,0 +1,12 @@
+# KEEP THIS COMMENT IN YOUR COPY.
+#
+# Don't delete this file if you want to keep keyword_check enabled even if it's
+# empty.
+#
+# See repohooks/README.md for more details.
+
+dummy
+master
+\bnative
+sanity
+slave