Move IcuRegistration class to external/icu

Move IcuRegistration class to external/icu for sharing with
other code.

See the associated change in external/icu.

Bug: 120493361
Test: See external/icu change
Change-Id: I3ddfa073b6dc40ac3fbc90e1cf5cecd8339a4e55
diff --git a/NativeCode.bp b/NativeCode.bp
index 38f57b3..e40b9bc 100644
--- a/NativeCode.bp
+++ b/NativeCode.bp
@@ -66,6 +66,7 @@
         "libz",
     ],
     static_libs: [
+        "libandroidicuinit",
         "libziparchive",
     ],
     target: {