Remove customer_testing adhoc.

The test was migrated to shard tests to the repo under test.

Bug: https://github.com/flutter/flutter/issues/139153
Change-Id: I3193aff04fc4831e8f5d87832112adb1bdb6e8ab
Reviewed-on: https://flutter-review.googlesource.com/c/recipes/+/52701
Commit-Queue: Godofredo Contreras <godofredoc@google.com>
Reviewed-by: Christopher Fujino <fujino@google.com>
diff --git a/recipe_modules/adhoc_validation/api.py b/recipe_modules/adhoc_validation/api.py
index bb0e389..5180fc8 100644
--- a/recipe_modules/adhoc_validation/api.py
+++ b/recipe_modules/adhoc_validation/api.py
@@ -17,8 +17,8 @@
   def available_validations(self):
     """Returns the list of accepted validations."""
     return [
-        'analyze', 'customer_testing', 'docs', 'fuchsia_precache',
-        'verify_binaries_codesigned', 'docs_deploy'
+        'analyze', 'docs', 'fuchsia_precache', 'verify_binaries_codesigned',
+        'docs_deploy'
     ]
 
   def run(self, name, validation, env, env_prefixes, secrets=None):
diff --git a/recipe_modules/adhoc_validation/resources/customer_testing.bat b/recipe_modules/adhoc_validation/resources/customer_testing.bat
deleted file mode 100644
index 8ab6e83..0000000
--- a/recipe_modules/adhoc_validation/resources/customer_testing.bat
+++ /dev/null
@@ -1,10 +0,0 @@
-REM Copyright 2020 The Chromium Authors. All rights reserved.
-REM Use of this source code is governed by a BSD-style license that can be
-REM found in the LICENSE file.
-
-REM The customer testing requires both the branch under test and master to be checked out.
-git fetch origin master
-git checkout master
-git checkout %REVISION%
-CD dev/customer_testing/
-CALL ci.bat
diff --git a/recipe_modules/adhoc_validation/resources/customer_testing.sh b/recipe_modules/adhoc_validation/resources/customer_testing.sh
deleted file mode 100644
index 1f9595b..0000000
--- a/recipe_modules/adhoc_validation/resources/customer_testing.sh
+++ /dev/null
@@ -1,16 +0,0 @@
-#!/bin/bash
-
-# Copyright 2020 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.
-
-set -e
-
-# Customer testing require both master and the branch
-# under test to be checkout out.
-
-git fetch origin master
-git checkout master
-git checkout $REVISION
-cd dev/customer_testing/
-bash ci.sh