Fix 1ES Hosted Pool image demands (#737)

* Fix 1ES Hosted Pool image demands (#734)

* Remove unused yml files

Author: Francisco-Gamino

azure-pipelines-1.yml

@@ -9,7 +9,8 @@
 
 pool:
     name: '1ES-Hosted-AzFunc'
-    vmImage: 'MMS2019TLS'
+    demands:
+      - ImageOverride -equals MMS2019TLS
 
 variables:
   Configuration: Release