Move sequence_number_utils.h to rtc_base/

Bug: webrtc:8440
Change-Id: I36e70da6ce70b95db7d3fce8b0013bff5c795bfc
Reviewed-on: https://webrtc-review.googlesource.com/14860
Reviewed-by: Karl Wiberg <kwiberg@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Björn Terelius <terelius@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20429}
diff --git a/modules/remote_bitrate_estimator/BUILD.gn b/modules/remote_bitrate_estimator/BUILD.gn
index e394b81..adfb2e2 100644
--- a/modules/remote_bitrate_estimator/BUILD.gn
+++ b/modules/remote_bitrate_estimator/BUILD.gn
@@ -141,6 +141,7 @@
       "../../rtc_base:gtest_prod",
       "../../rtc_base:rtc_base",
       "../../rtc_base:rtc_base_approved",
+      "../../rtc_base:rtc_numerics",
       "../../system_wrappers",
       "../../test:test_support",
       "../../voice_engine",