Run Mus Demo and WS tests on Ozone Linux bot

tools/mb/mb_config.pyl

Index: tools/mb/mb_config.pyl
diff --git a/tools/mb/mb_config.pyl b/tools/mb/mb_config.pyl
index a74172d27d9bd27c16baee8a45f502a0f9239f62..ceb275175ccae2009a9fa0c16e053fa6db389fcc 100644
--- a/tools/mb/mb_config.pyl
+++ b/tools/mb/mb_config.pyl
@@ -564,6 +564,7 @@
       'linux_chromium_gn_upload': 'gn_linux_upload',
       'linux_chromium_headless_rel': 'headless_linux_release_trybot',
       'linux_chromium_ozone_compile_only_ng': 'ozone_linux_release_trybot',
+      'linux_chromium_ozone_ng': 'ozone_linux_release_trybot',
 
       # This is intentionally a release_bot and not a release_trybot;
       # enabling DCHECKs seems to cause flaky failures that don't show up
@@ -1817,7 +1818,8 @@
     },
 
     'ozone_linux': {
-      'gn_args': ('ozone_auto_platforms=false ozone_platform_wayland=true '
+      'gn_args': ('ozone_auto_platforms=false ozone_platform_wayland=true'
+                  'ozone_platform_headless=true '
                   'ozone_platform_x11=true ozone_platform_gbm=true '
                   'enable_package_mash_services=true use_ash=false '
                   'use_jessie_sysroot=true use_xkbcommon=true'),