[signin][android] Remove unnecessary includes in signin_manager_android

This removes unused includes from signin_manager_android.cc to
primary_account_manager and primary_account_mutator. Including the DEPS
exception for primary_account_manager which is internal to
identity_manager.

Bug: 934688
Change-Id: I85a84245d0bb3e12bf4746f603d0051926b6a430
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1862445
Commit-Queue: Boris Sazonov <bsazonov@chromium.org>
Auto-Submit: Pâris Meuleman <pmeuleman@chromium.org>
Reviewed-by: Boris Sazonov <bsazonov@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705997}

chrome/browser/android/signin/DEPS

-specific_include_rules = {
-  # Exception while there's no solution for the fact that SetPrimaryAccount()
-  # expects an account ID (which on Android is the Gaia ID), but we receive an
-  # email address instead along with SigninManagerAndroid::OnSignInCompleted().
-  "signin_manager_android\.cc": [
-    "+components/signin/internal/identity_manager/primary_account_manager.h",
-  ],
-}

chrome/browser/android/signin/signin_manager_android.cc

@@ -13,9 +13,7 @@
 #include "chrome/android/chrome_jni_headers/SigninManager_jni.h"
 #include "chrome/common/pref_names.h"
 #include "components/prefs/pref_service.h"
-#include "components/signin/internal/identity_manager/primary_account_manager.h"
 #include "components/signin/public/base/signin_pref_names.h"
-#include "components/signin/public/identity_manager/primary_account_mutator.h"
 #include "google_apis/gaia/gaia_auth_util.h"
 
 #include "base/android/callback_android.h"