Add a bug number in the TODO tag

- ICU4C is kept in PRODUCT_PACKAGES for the app compat issue

Bug: 124218500
Test: Treehugger
Change-Id: I9b98321c639e99c59e6a5ea45dd380f5f731a419
diff --git a/target/product/runtime_libart.mk b/target/product/runtime_libart.mk
index f1f807d..fa35d43 100644
--- a/target/product/runtime_libart.mk
+++ b/target/product/runtime_libart.mk
@@ -33,7 +33,7 @@
 PRODUCT_PACKAGES += \
     ext \
 
-# Libcore ICU. TODO: Try to figure out if/why we need them explicitly.
+# Libcore ICU. TODO(b/124218500): Remove them explicitly when the bug is resolved.
 PRODUCT_PACKAGES += \
     libicui18n \
     libicuuc \