Enable "gn check" on android GN bots

testing/buildbot/chromium.linux.json

 {
   "Android GN": {
     "additional_compile_targets": [
       "chrome_public_apk",
       "chrome_public_test_apk",
       "chrome_shell_apk",
       "chrome_shell_test_apk",
       "content_shell_apk",
       "mandoline:all"
     ],
@@ skipping 36 matching lines @@
       },
       {
         "test": "mojo_view_manager_lib_unittests"
       },
       {
         "test": "resource_provider_unittests"
       },
       {
         "test": "view_manager_unittests"
       }
+    ],
+    "scripts": [
+      {
+        "name": "gn_check",
+        "script": "gn_check.py"

[tfarina, 2015/07/09 18:56:27]

only in release? Do we want to do this in the debug config too? (I think this is
more a question to Dirk though).

+      }
     ]
   },
   "Android GN (dbg)": {
     "additional_compile_targets": [
       "chrome_public_apk",
       "chrome_public_test_apk",
       "chrome_shell_apk",
       "chrome_shell_test_apk",
       "content_shell_apk",
       "content_shell_test_apk",
@@ skipping 1354 matching lines @@
       }
     ],
     "scripts": [
       {
         "name": "nacl_integration",
         "script": "nacl_integration.py"
       }
     ]
   }
 }