Roll third_party/icu/ 163e29159..9408c6fd4 (4 commits)

https://chromium.googlesource.com/chromium/deps/icu.git/+log/163e29159ecb..9408c6fd4a39

Created with:
  roll-dep third_party/icu

Change-Id: I5b13be19c67f0674bcdee45cd9a8ee775cb856f8
Reviewed-on: https://pdfium-review.googlesource.com/c/pdfium/+/122715
Reviewed-by: Lei Zhang <thestig@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
diff --git a/DEPS b/DEPS
index b4836c7..2fbd0f6 100644
--- a/DEPS
+++ b/DEPS
@@ -124,7 +124,7 @@
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling icu
   # and whatever else without interference from each other.
-  'icu_revision': '163e29159ecb39d4c165c48272e565614a1e024a',
+  'icu_revision': '9408c6fd4a39e6fef0e1c4077602e1c83b15f3fb',
   # Three lines of non-changing comments so that
   # the commit queue can handle CLs rolling instrumented_lib
   # and whatever else without interference from each other.