message: Remove Win UWP mb config
  Cr-Commit-Position: refs/heads/master@{#34134}
diff: 'Win64 Debug (Clang)': 'win_clang_debug_bot_x64',
  'Win64 Release (Clang)': 'win_clang_release_bot_x64',
  'Win64 ASan': 'win_asan_clang_release_bot_x64',
  - 'Win64 UWP': 'win_uwp_release_bot_x64',
  'Win (more configs)': {
  'bwe_test_logging':
  'bwe_test_logging_x86',
  'win_asan': 'win_asan_clang_release_bot_x64',
  'win_x64_clang_dbg_win8': 'win_clang_debug_bot_x64',
  'win_x64_clang_dbg_win10': 'win_clang_debug_bot_x64',
  - 'win_x64_uwp': 'win_uwp_release_bot_x64',
  'win_x86_more_configs': {
  'bwe_test_logging':
  'bwe_test_logging_x86',
  'asan', 'clang', 'full_symbols', 'openh264', 'release_bot', 'x64',
  'win_fastlink',
  ],
  - 'win_uwp_release_bot_x64': [
  - # UWP passes compiler flags that are not supported by goma.
  - 'no_clang', 'openh264', 'x64', 'winuwp', 'release_bot_no_goma'
  - ],
  # Mac
  'mac_asan_clang_release_bot_x64': [
  'gn_args': 'rtc_enable_sctp=false',
  },
  - 'winuwp': {
  - 'gn_args': 'target_os="winuwp"',
  - },
  -
  'win_undef_unicode': {
  'gn_args': 'rtc_win_undef_unicode=true',
  },
  