Change mojo application name to {name}.mojo

sky/tools/debugger/prompt/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-shared_library("prompt") {
+import("//mojo/public/mojo_application.gni")
+
+mojo_binary_application("prompt") {
   output_name = "sky_debugger_prompt"
 
   sources = [
     "prompt.cc",
   ]
 
   deps = [
     "//base",
     "//mojo/application",
     "//mojo/public/c/system:for_shared_library",
     "//mojo/public/cpp/bindings",
     "//mojo/public/cpp/utility",
     "//sky/tools/debugger:bindings",
     "//sky/viewer:bindings",
   ]
 }