[release/6.0] Use 1ES machines for official builds (#39683)

* [release/6.0] Use 1ES machines for official builds

Originally also included changes from:
Co-authored-by: Brennan <brecon@microsoft.com>
Co-authored-by: Hao Kung <HaoK@users.noreply.github.com>

.azure/pipelines/ci.yml

@@ -768,7 +768,8 @@ stages:
           # In addition to the dependencies above, ensure the build was successful overall.
           - Source_Build_Managed
         pool:
-          vmImage: windows-latest
+          name: NetCore1ESPool-Svc-Internal
+          demands: ImageOverride -equals Build.Server.Amd64.VS2019
         publishUsingPipelines: ${{ variables._PublishUsingPipelines }}
         enablePublishBuildArtifacts: true # publish artifacts/log files
 

.azure/pipelines/jobs/default-build.yml

@@ -97,9 +97,9 @@ jobs:
       ${{ if eq(parameters.agentOs, 'macOS') }}:
         vmImage: macOS-10.15
       ${{ if eq(parameters.agentOs, 'Linux') }}:
-        ${{ if eq(parameters.useHostedUbuntu, true) }}:
+        ${{ if and(eq(parameters.useHostedUbuntu, true), or(ne(variables['System.TeamProject'], 'internal'), in(variables['Build.Reason'], 'Manual', 'PullRequest', 'Schedule'))) }}:
           vmImage: ubuntu-18.04
-        ${{ if eq(parameters.useHostedUbuntu, false) }}:
+        ${{ if or(eq(parameters.useHostedUbuntu, false), and(eq(variables['System.TeamProject'], 'internal'), notin(variables['Build.Reason'], 'Manual', 'PullRequest', 'Schedule'))) }}:
           ${{ if eq(variables['System.TeamProject'], 'public') }}:
             name: NetCore1ESPool-Svc-Public
             demands: ImageOverride -equals Build.Ubuntu.1804.Amd64.Open