[release/3.1] Clean out Ubuntu 16.04 testing

- a variant of #32894
  - use Ubuntu 18.04 agents for testing in Docker containers on Helix
- remove use of old Centos and Debian queues
- move to newer OSX.1014.Amd64.Open queue and Fedora.33.Amd64.Open Docker image
- add a couple of queues we test against in 'main'

Author: dougbu

eng/targets/Helix.Common.props

@@ -18,23 +18,22 @@
     <HelixAvailableTargetQueue Include="Windows.81.Amd64.Open" Platform="Windows" />
     <HelixAvailableTargetQueue Include="Windows.7.Amd64.Open" Platform="Windows" />
     <HelixAvailableTargetQueue Include="Windows.10.Amd64.EnterpriseRS3.ASPNET.Open" Platform="Windows" EnableByDefault="false" />
-    <HelixAvailableTargetQueue Include="OSX.1013.Amd64.Open" Platform="OSX" />
-    <HelixAvailableTargetQueue Include="Ubuntu.1604.Amd64.Open" Platform="Linux" />
+    <HelixAvailableTargetQueue Include="OSX.1014.Amd64.Open" Platform="OSX" />
+    <HelixAvailableTargetQueue Include="OSX.1100.Amd64.Open" Platform="OSX" />
     <HelixAvailableTargetQueue Include="Ubuntu.1804.Amd64.Open" Platform="Linux" />
-    <HelixAvailableTargetQueue Include="Centos.7.Amd64.Open" Platform="Linux" />
-    <HelixAvailableTargetQueue Include="Debian.8.Amd64.Open" Platform="Linux" />
+    <HelixAvailableTargetQueue Include="Ubuntu.2004.Amd64.Open" Platform="Linux" />
     <HelixAvailableTargetQueue Include="Debian.9.Amd64.Open" Platform="Linux" />
     <HelixAvailableTargetQueue Include="Redhat.7.Amd64.Open" Platform="Linux" />
-    <HelixAvailableTargetQueue Include="(Fedora.28.Amd64.Open)Ubuntu.1604[email protected]/dotnet-buildtools/prereqs:fedora-28-helix-09ca40b-20190508143249" Platform="Linux" />
+    <HelixAvailableTargetQueue Include="(Fedora.33.Amd64.Open)Ubuntu.1804[email protected]/dotnet-buildtools/prereqs:fedora-33-helix-20210120000908-a9df267" Platform="Linux" />
   </ItemGroup>
 
   <ItemGroup Condition="'$(IsWindowsOnlyTest)' != 'true' AND '$(TargetArchitecture)' == 'arm64'">
     <!-- arm64 queues -->
-    <HelixAvailableTargetQueue Include="(Debian.9.Arm64.Open)[email protected]/dotnet-buildtools/prereqs:debian-9-helix-arm64v8-a12566d-20190807161036" Platform="Linux" />
+    <HelixAvailableTargetQueue Include="Ubuntu.1804.ArmArch.Open" Platform="Linux" />
+    <HelixAvailableTargetQueue Include="(Debian.9.Arm64.Open)[email protected]/dotnet-buildtools/prereqs:debian-9-helix-arm64v8-a12566d-20190807161036" Platform="Linux" />
 
     <!-- Need to resolve permission issues on this docker queue
-    <HelixAvailableTargetQueue Include="(Alpine.38.Arm64)[email protected]/dotnet-buildtools/prereqs:alpine-3.8-helix-arm64v8-46e69dd-20190327215724" Platform="Linux" />
-    <HelixAvailableTargetQueue Include="(Ubuntu-1804.Arm64.Open)[email protected]/dotnet-buildtools/prereqs:ubuntu-18.04-helix-arm64v8-6f28fa9-20190606004102" Platform="Linux" />
+    <HelixAvailableTargetQueue Include="(Alpine.38.Arm64)[email protected]/dotnet-buildtools/prereqs:alpine-3.8-helix-arm64v8-46e69dd-20190327215724" Platform="Linux" />
     -->
   </ItemGroup>