Chromecast: unbundle ICU data file from the binary build.

Chromecast platform has multiple binaries that each link in the data
file; this results in some wasted disk footprint.

R=lcwu@chromium.org,thakis@chromium.org
BUG=446387

Review URL: https://codereview.chromium.org/833183004

Cr-Commit-Position: refs/heads/master@{#310174}

build/common.gypi

@@ -967,10 +967,10 @@
         }],
 
         # By default, use ICU data file (icudtl.dat) on all platforms
-        # except when building Android WebView or Chromecast.
+        # except when building Android WebView.
         # TODO(jshin): Handle 'use_system_icu' on Linux (Chromium).
         # Set the data reduction proxy origin for Android Webview.
-        ['android_webview_build==0 and android_webview_telemetry_build==0 and chromecast==0', {
+        ['android_webview_build==0 and android_webview_telemetry_build==0', {
           'icu_use_data_file_flag%' : 1,
         }, {
           'icu_use_data_file_flag%' : 0,