Fix foreground file_manager_commands and import_controller BUILD rules

 - ImportController @types refer to {CommandHandlerDeps}
  - add externs_list deps UI externs/command_handler_deps.js
 - And the same for FileManagerCommands

No change in test behavior.

Bug: 914197
Change-Id: I9f71b677f22961d0e14ac55834ca0a9b0cea180a
Reviewed-on: https://chromium-review.googlesource.com/c/1373051Reviewed-by: Sam McNally <sammc@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#615810}

ui/file_manager/file_manager/foreground/js/BUILD.gn

@@ -360,6 +360,7 @@ js_library("file_manager_commands") {
     "ui:file_manager_ui",
     "//ui/webui/resources/cr_elements/cr_input:cr_input",
   ]
+  externs_list = [ "//ui/file_manager/externs/command_handler_deps.js" ]
 }
 
 js_library("file_selection") {
@@ -460,6 +461,7 @@ js_library("import_controller") {
     "ui:directory_tree",
     "ui:file_manager_ui",
   ]
+  externs_list = [ "//ui/file_manager/externs/command_handler_deps.js" ]
 }
 
 js_library("last_modified_controller") {