Skip Helix tests when skipping tests (#37171)

- also make `Skip tests?` option visible when starting manual runs

Author: dougbu

.azure/pipelines/ci.yml

@@ -18,6 +18,13 @@ pr:
     include:
     - '*'
 
+# Choose whether to skip tests when running pipeline manually.
+parameters:
+- name: skipTests
+  default: false
+  displayName: Skip tests?
+  type: boolean
+
 variables:
 - name: DOTNET_SKIP_FIRST_TIME_EXPERIENCE
   value: true
@@ -639,11 +646,10 @@ stages:
       parameters:
         inputName: Linux_musl_arm64
 
-  - ${{ if or(eq(variables['System.TeamProject'], 'public'), in(variables['Build.Reason'], 'PullRequest'), in(variables['Build.Reason'], 'Manual')) }}:
+  - ${{ if and(ne(parameters.skipTests, 'true'), or(eq(variables['System.TeamProject'], 'public'), in(variables['Build.Reason'], 'PullRequest'), in(variables['Build.Reason'], 'Manual'))) }}:
     # Test jobs
     - template: jobs/default-build.yml
       parameters:
-        condition: ne(variables['SkipTests'], 'true')
         jobName: Windows_Test
         jobDisplayName: "Test: Windows Server 2016 x64"
         agentOs: Windows
@@ -669,7 +675,6 @@ stages:
 
     - template: jobs/default-build.yml
       parameters:
-        condition: ne(variables['SkipTests'], 'true')
         jobName: MacOS_Test
         jobDisplayName: "Test: macOS 10.15"
         agentOs: macOS
@@ -691,7 +696,6 @@ stages:
 
     - template: jobs/default-build.yml
       parameters:
-        condition: ne(variables['SkipTests'], 'true')
         jobName: Linux_Test
         jobDisplayName: "Test: Ubuntu 18.04 x64"
         agentOs: Linux