Rename update_manifest_unittest.cc in browser/component_updater/

Change https://codereview.chromium.org/74893002 introduced chrome/browser/component_updater/test/update_manifest_unittest.cc,
but a file with the same basename already exists in common/extensions/.
This causes runhooks to fail when running android_gyp on downstream bots.

TBR=waffles@chromium.org,cpu@chromium.org,cdn@chromium.org
BUG=323139

Review URL: https://codereview.chromium.org/85603002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237081 0039d316-1c4b-4281-b951-d872f2087c98

chrome/chrome_tests_unit.gypi

@@ -756,7 +756,7 @@
         'browser/component_updater/test/component_patcher_unittest.cc',
         'browser/component_updater/test/component_updater_service_unittest.cc',
         'browser/component_updater/test/test_installer.cc',
-        'browser/component_updater/test/update_manifest_unittest.cc',
+        'browser/component_updater/test/component_updater_manifest_unittest.cc',
         'browser/component_updater/test/url_request_post_interceptor.cc',
         'browser/content_settings/content_settings_default_provider_unittest.cc',
         'browser/content_settings/content_settings_mock_observer.cc',