Use a total global counter

scripts/azure-pipelines-variables.yml

@@ -8,7 +8,7 @@ variables:
   FEATURE_NAME: ''
   PREVIEW_LABEL: 'preview'
   BUILD_NUMBER: $[counter(format('_{0}_{1}_{2}__', variables['SKIASHARP_VERSION'], variables['Build.SourceBranch'], variables['PREVIEW_LABEL']), 1)]
-  BUILD_COUNTER: $[counter(format('{0}', variables['Build.SourceBranch']), 300)]
+  BUILD_COUNTER: $[counter('global_counter', 301)]
   TIZEN_LINUX_PACKAGES: libxcb-xfixes0 libxcb-render-util0 libwebkitgtk-1.0-0 libxcb-image0 acl libsdl1.2debian libv4l-0 libxcb-randr0 libxcb-shape0 libxcb-icccm4 libsm6 gettext rpm2cpio cpio bridge-utils openvpn
   MANAGED_LINUX_PACKAGES: ttf-ancient-fonts ninja-build
   MONO_VERSION_MACOS: '6_12_13'