Fix UnusedResoruces android lint warning in castshell_java

chromecast/browser/android/BUILD.gn

Index: chromecast/browser/android/BUILD.gn
diff --git a/chromecast/browser/android/BUILD.gn b/chromecast/browser/android/BUILD.gn
index 358c11f960c59633e88c8b9619223c2d4a57f201..4b69a941ef796974194d4a7fcde3e961ccae2d0c 100644
--- a/chromecast/browser/android/BUILD.gn
+++ b/chromecast/browser/android/BUILD.gn
@@ -6,13 +6,16 @@ import("//build/config/android/rules.gni")
 
 assert(is_android)
 
+cast_shell_android_manifest =
+    "$root_gen_dir/cast_shell_manifest/AndroidManifest.xml"
+
 jinja_template("cast_shell_manifest") {
   input = "apk/AndroidManifest.xml.jinja2"
-  output = "$root_gen_dir/cast_shell_manifest/AndroidManifest.xml"
+  output = cast_shell_android_manifest
 }
 
 android_resources("cast_shell_android_resources") {
-  android_manifest = "$root_gen_dir/cast_shell_manifest/AndroidManifest.xml"
+  android_manifest = cast_shell_android_manifest
   android_manifest_dep = ":cast_shell_manifest"
   resource_dirs = [ "//chromecast/browser/android/apk/res" ]
 }
@@ -32,8 +35,11 @@ android_library("cast_shell_java") {
     "$java_src_dir/org/chromium/chromecast/shell/CastWindowManager.java",
   ]
 
+  android_manifest = cast_shell_android_manifest
+
   deps = [
     ":cast_shell_android_resources",
+    ":cast_shell_manifest",
     "//base:base_java",
     "//chromecast/base:base_java",
     "//content/public/android:content_java",