Revert "update_engine: Support milestones to EOL from Omaha"

This reverts commit 893cae4b0e5141bcaf9f56b1775e681c8f523630.

Reason for revert: use of EOL date and EOL notification date instead milestones to EOL.

Original change's description:
> update_engine: Support milestones to EOL from Omaha
>
> Initiative to show EOL message on Chrome OS devices require that
> update_engine parses the fields within Omaha response that pertain to the
> new milestones to EOL field. The Omaha response will include a new
> field called "milestones_to_eol" which will be an integer value
> string.
>
> The job of update_engine when it comes to milestones to EOL from Omaha
> is to merely forward. No checks and no modifications of fields are
> done within update_engine besides being able to convert the milestones
> to EOL from a string to integer.
>
> BUG=chromium:994999
> TEST=FEATURES="test" emerge-$BOARD update_engine update_engine-client
> TEST=cros deploy $IP update_engine update_engine-client
> TEST=test_that -b $BOARD $IP autoupdate_EOL # from Cq-Depend
> TEST=test_that -b $BOARD $IP autoupdate_EOL.milestones # from Cq-Depend
>
> Cq-Depend:chromium:1761371
> Change-Id: I268e4c8e641b17d6a727a50f53285cc97c76eb22
> Reviewed-on: https://chromium-review.googlesource.com/1759285
> Tested-by: Jae Hoon Kim <kimjae@chromium.org>
> Commit-Ready: ChromeOS CL Exonerator Bot <chromiumos-cl-exonerator@appspot.gserviceaccount.com>
> Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
> Reviewed-by: Nicolas Norvez <norvez@chromium.org>
> Reviewed-by: Amin Hassani <ahassani@chromium.org>

TBR=maybelle@chromium.org,norvez@chromium.org,ahassani@chromium.org,abutzier@chromium.org,chromiumos-cl-exonerator@appspot.gserviceaccount.com,kimjae@chromium.org

BUG=chromium:994999
TEST=none
Cq-Depend:chromium:1782971
Change-Id: I42e75e22948b3653500d355027dc3312015c9ebf
Reviewed-on: https://chromium-review.googlesource.com/c/aosp/platform/system/update_engine/+/1782970
Tested-by: Jae Hoon Kim <kimjae@chromium.org>
Commit-Queue: Jae Hoon Kim <kimjae@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Amin Hassani <ahassani@chromium.org>
diff --git a/client_library/client_dbus.cc b/client_library/client_dbus.cc
index 3c23de4..e6aba92 100644
--- a/client_library/client_dbus.cc
+++ b/client_library/client_dbus.cc
@@ -271,9 +271,8 @@
   return proxy_->GetLastAttemptError(last_attempt_error, nullptr);
 }
 
-bool DBusUpdateEngineClient::GetEolStatus(int32_t* eol_status,
-                                          int32_t* milestones_to_eol) const {
-  return proxy_->GetEolStatus(eol_status, milestones_to_eol, nullptr);
+bool DBusUpdateEngineClient::GetEolStatus(int32_t* eol_status) const {
+  return proxy_->GetEolStatus(eol_status, nullptr);
 }
 
 }  // namespace internal