Use bundle_data and create_bundle to add support for iOS app bundle.

Cherry-pick 0c9a7809 to m49 branch.

Original CL: https://codereview.chromium.org/1755473004/

BUG=297668
TBR=dpranke@chromium.org,sdefresne

Review URL: https://codereview.chromium.org/1785033005 .

BUILD.gn

@@ -541,10 +541,9 @@ if (is_android) {
 # TODO(GYP) support use_system_icu.
 if (icu_use_data_file) {
   if (is_ios) {
-    group("icudata") {
-      # TODO(GYP): Provide an empty group so that this target does not
-      # unconditionally fail. The dat file needs to be bundled separately. In
-      # the longer term, need to figure out how to use system ICU
+    bundle_data("icudata") {
+      sources = [ "source/data/in/icudtl.dat" ]
+      outputs = [ "{{bundle_resources_dir}}/{{source_file_part}}" ]
     }
   } else {
     copy("icudata") {