Merge some straggling master fixes down to preview2 (#19707)

Co-authored-by: Hao Kung <HaoK@users.noreply.github.com>
Co-authored-by: James Newton-King <james@newtonking.com>
Co-authored-by: Doug Bunting <6431421+dougbu@users.noreply.github.com>

.azure/pipelines/ci.yml

@@ -683,7 +683,7 @@ stages:
   # Helix ARM64
   - template: jobs/default-build.yml
     parameters:
-      condition: notin(variables['Build.Reason'], 'PullRequest')
+      condition: and(eq(variables['System.TeamProject'], 'public'), notin(variables['Build.Reason'], 'PullRequest'))
       jobName: Helix_arm64_daily
       jobDisplayName: "Tests: Helix ARM64 Daily"
       agentOs: Linux

eng/targets/Helix.Common.props

@@ -37,7 +37,7 @@
     <HelixAvailableTargetQueue Include="(Fedora.28.Amd64.Open)Ubuntu.1604.Amd64.Open@mcr.microsoft.com/dotnet-buildtools/prereqs:fedora-28-helix-09ca40b-20190508143249" Platform="Linux" />
   </ItemGroup>
 
-  <ItemGroup Condition="'$(IsWindowsOnlyTest)' != 'true' AND '$(TargetArchitecture)' == 'arm64' AND '$(IsHelixDaily)' == 'true'">
+  <ItemGroup Condition="'$(IsWindowsOnlyTest)' != 'true' AND '$(TargetArchitecture)' == 'arm64' AND '$(IsHelixDaily)' == 'true' AND '$(RunQuarantinedTests)' != 'true'">
     <!-- arm64 queues -->
     <HelixAvailableTargetQueue Include="(Debian.9.Arm64.Open)Ubuntu.1804.Armarch.Open@mcr.microsoft.com/dotnet-buildtools/prereqs:debian-9-helix-arm64v8-a12566d-20190807161036" Platform="Linux" />
 

src/Servers/Kestrel/test/InMemory.FunctionalTests/Http2/Http2ConnectionTests.cs

@@ -225,7 +225,7 @@ namespace Microsoft.AspNetCore.Server.Kestrel.Core.Tests
             await StartStreamAsync(1, _browserRequestHeaders, endStream: true);
 
             await ExpectAsync(Http2FrameType.HEADERS,
-                withLength: 37,
+                withLength: 33,
                 withFlags: (byte)Http2HeadersFrameFlags.END_HEADERS,
                 withStreamId: 1);
             await ExpectAsync(Http2FrameType.DATA,