Send all of the icon URLs listed in Web Manifest to WebAPK Server.

chrome/android/webapk/shell_apk/BUILD.gn

Index: chrome/android/webapk/shell_apk/BUILD.gn
diff --git a/chrome/android/webapk/shell_apk/BUILD.gn b/chrome/android/webapk/shell_apk/BUILD.gn
index fb6fabed50357b3b602de6db31d4302a82111f36..c2a637d9f4a3cb8b88348387e9d0ef14d7e66c88 100644
--- a/chrome/android/webapk/shell_apk/BUILD.gn
+++ b/chrome/android/webapk/shell_apk/BUILD.gn
@@ -25,9 +25,11 @@ declare_args() {
   webapk_orientation = "portrait"
   webapk_theme_color = "2147483648L"  # HostBrowserLauncher#MANIFEST_COLOR_INVALID_OR_MISSING
   webapk_background_color = "2147483648L"  #HostBrowserLauncher#MANIFEST_COLOR_INVALID_OR_MISSING
+  webapk_icon_urls =
+      "http://www.template.com/icon1.png; http://www.template.com/icon2.png"
 
   # The URL of the app icon. Empty if the app icon is generated.
-  webapk_icon_url = "http://www.template.com/icon.png"
+  webapk_icon_url = "http://www.template.com/icon1.png"
 
   # Murmur2 hash of the homescreen icon. The hash should be of the icon as it is
   # available from the web. The icon bytes should not be transformed (e.g.
@@ -68,8 +70,9 @@ jinja_template("shell_apk_manifest") {
     "orientation=$webapk_orientation",
     "theme_color=$webapk_theme_color",
     "background_color=$webapk_background_color",
-    "icon_url=$webapk_icon_url",
+    "best_icon_url=$webapk_icon_url",
     "icon_murmur2_hash=$webapk_icon_murmur2_hash",
+    "icon_urls=$webapk_icon_urls",
     "scope_url_host=$webapk_scope_url_host",
     "scope_url_path=$webapk_scope_url_path",
     "web_manifest_url=$webapk_web_manifest_url",