Update FormRecognizer Tests.yml to auto-narrow when running against canary (Azure#12384)

* update the tests

* correct not condition

* attempt conditional variable

* whitespace corrections

* additional clarification on comments

Author: scbedd

sdk/formrecognizer/tests.yml

@@ -5,6 +5,37 @@ jobs:
     parameters:
       BuildTargetingString: azure-ai-formrecognizer
       ServiceDirectory: formrecognizer
+      # This is a specific request from the formrecognizer service team
+      # their claim is that the full matrix ends up stress-testing their service. 
+      # As such, the canary test runs should run on a reduced matrix.
+      ${{ if contains(variables['Build.DefinitionName'], 'prod') }}:
+        Matrix:
+          Linux_Python35:
+            OSVmImage: 'ubuntu-18.04'
+            PythonVersion: '3.5'
+          MacOs_Python37:
+            OSVmImage: 'macOS-10.15'
+            PythonVersion: '3.7'
+          Windows_Python27:
+            OSVmImage: 'windows-2019'
+            PythonVersion: '2.7'
+          Linux_PyPy3:
+            OSVmImage: 'ubuntu-18.04'
+            PythonVersion: 'pypy3'
+          Linux_Python38:
+            OSVmImage: 'ubuntu-18.04'
+            PythonVersion: '3.8'
+      ${{ if not(contains(variables['Build.DefinitionName'], 'prod')) }}:
+        Matrix:
+          Linux_Python35:
+            OSVmImage: 'ubuntu-18.04'
+            PythonVersion: '3.5'
+          Windows_Python27:
+            OSVmImage: 'windows-2019'
+            PythonVersion: '2.7'
+          Linux_Python38:
+            OSVmImage: 'ubuntu-18.04'
+            PythonVersion: '3.8'
       EnvVars:
         AZURE_SUBSCRIPTION_ID: $(provisioner-subscription)
         AZURE_TENANT_ID: $(aad-azure-sdk-test-tenant-id)