[Fuchsia] Always use dummy reboot on Fuchsia regardless of branding.

Bug: 152233113
Change-Id: I5a4a55c9e9bee40ca29b1089757a2eee4a5d2a76
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2118691Reviewed-by: Yuchen Liu <yucliu@chromium.org>
Commit-Queue: David Rees <drees@google.com>
Cr-Commit-Position: refs/heads/master@{#753096}

chromecast/system/reboot/BUILD.gn

@@ -13,7 +13,7 @@ cast_source_set("reboot_util") {
 
   deps = [ "//base" ]
 
-  if (chromecast_branding == "google") {
+  if (chromecast_branding == "google" && !is_fuchsia) {
     deps += [ "//chromecast/internal/system/reboot:reboot_util" ]
   } else {
     sources += [ "reboot_util_dummy.cc" ]