Reland "🛃 Move Custom Tabs example into Chromium."

This CL is a reland of the following CL. It fixes the issues that
produced lint warnings.

https://chromium-review.googlesource.com/c/chromium/src/+/2120724

TBR=dominickn@chromium.org, twellington@chromium.org, agrieve@chromium.org, yfriedman@chromium.org

Bug: 980567
Change-Id: Ia48f18c9f10ce3a2239781d0c97174de4d234d7f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2142251
Reviewed-by: Peter Conn <peconn@chromium.org>
Reviewed-by: Yaron Friedman <yfriedman@chromium.org>
Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Peter Conn <peconn@chromium.org>
Cr-Commit-Position: refs/heads/master@{#758858}

diff --git a/BUILD.gn b/BUILD.gn
index 6bb4d97..6552bd7 100644
--- a/BUILD.gn
+++ b/BUILD.gn

@@ -385,10 +385,10 @@
         "//chrome/android:chrome_public_apk",
         "//chrome/android:chrome_public_test_apk",
         "//chrome/android/features/media_router:media_router_junit_tests",
+        "//chrome/browser/android/examples/custom_tabs_client:custom_tabs_client_example_apk",
         "//chrome/browser/android/examples/partner_browser_customizations_provider:partner_browser_customizations_example_apk",
         "//chrome/test/chromedriver/test/webview_shell:chromedriver_webview_shell_apk",
         "//content/shell/android:content_shell_test_apk",
-        "//third_party/custom_tabs_client:custom_tabs_client_example_apk",
       ]
     }