[gn] Switch android bots to gn

gypfiles/standalone.gypi

 # Copyright 2012 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
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       }],
       ['OS=="android"', {
         # Location of Android NDK.
         'variables': {
           'variables': {
             # The Android toolchain needs to use the absolute path to the NDK
             # because it is used at different levels in the GYP files.
             'android_ndk_root%': '<(base_dir)/third_party/android_tools/ndk/',
             'android_host_arch%': "<!(uname -m | sed -e 's/i[3456]86/x86/')",
             # Version of the NDK. Used to ensure full rebuilds on NDK rolls.
-            'android_ndk_version%': 'r11c',
+            'android_ndk_version%': 'r12b',
             'host_os%': "<!(uname -s | sed -e 's/Linux/linux/;s/Darwin/mac/')",
             'os_folder_name%': "<!(uname -s | sed -e 's/Linux/linux/;s/Darwin/darwin/')",
           },
 
           # Copy conditionally-set variables out one scope.
           'android_ndk_root%': '<(android_ndk_root)',
           'android_ndk_version%': '<(android_ndk_version)',
           'host_os%': '<(host_os)',
           'os_folder_name%': '<(os_folder_name)',
 
@@ skipping 1176 matching lines @@
               '-fsanitize=cfi-vcall',
               '-fsanitize=cfi-derived-cast',
               '-fsanitize=cfi-unrelated-cast',
             ],
           }],
         ],
       },
     }],
   ],
 }