Don't build the full FlutterTester bundle on Fuchsia. (#3629)

The flutter_tester executable works just fine.

shell/platform/darwin/BUILD.gn

@@ -7,9 +7,13 @@ assert(is_mac || is_ios)
 group("darwin") {
   if (is_mac) {
     deps = [
-      "desktop:shell_application_bundle",
       "desktop:shell_standalone",
     ]
+    if (!is_fuchsia_host) {
+      deps += [
+        "desktop:shell_application_bundle",
+      ]
+    }
   } else if (is_ios) {
     deps = [
       "ios:flutter_framework",

shell/platform/darwin/desktop/BUILD.gn

@@ -2,8 +2,6 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-import("//build/config/mac/rules.gni")
-
 assert(is_mac)
 
 source_set("mac_desktop_platform") {
@@ -44,7 +42,11 @@ executable("shell_standalone") {
   ]
 }
 
-resource_copy_mac("mac_desktop_resources") {
+if (!is_fuchsia_host) {
+
+  import("//build/config/mac/rules.gni")
+
+  resource_copy_mac("mac_desktop_resources") {
     app_name = "FlutterTester"
     if (is_fuchsia_host) {
       resources = [ "//third_party/icu/common/icudtl.dat" ]
@@ -52,9 +54,9 @@ resource_copy_mac("mac_desktop_resources") {
       resources = [ "//third_party/icu/android/icudtl.dat" ]
     }
     bundle_directory = "."
-}
+  }
 
-mac_app("shell_application_bundle") {
+  mac_app("shell_application_bundle") {
     app_name = "FlutterTester"
     info_plist = "Info.plist"
     xibs = [ "flutter_mac.xib" ]
@@ -63,4 +65,5 @@ mac_app("shell_application_bundle") {
       ":mac_desktop_platform",
       ":mac_desktop_resources",
     ]
+  }
 }