Add icu as a dependency on Android.

Turns out ICU is referenced by //base/test/BUILD.gn
which is loaded when we generate projects with GN for Android.

This adds ICU back for Android only (was removed in
https://codereview.webrtc.org/1417563006).

TBR=pbos@webrtc.org
NOTRY=true

Review URL: https://codereview.webrtc.org/1414853009

Cr-Commit-Position: refs/heads/master@{#10587}
diff --git a/setup_links.py b/setup_links.py
index d04b3bc..58588a9 100755
--- a/setup_links.py
+++ b/setup_links.py
@@ -84,6 +84,7 @@
     'third_party/android_tools',
     'third_party/appurify-python',
     'third_party/ashmem',
+    'third_party/icu',
     'third_party/ijar',
     'third_party/jsr-305',
     'third_party/junit',