Adding release_build:true property to windows builders. (flutter#37397)

This will run the specified jobs under the release builder
recipe in dart-internal.

Bug:b/232552448

Author: yusuf-goog

.ci.yaml

@@ -467,13 +467,15 @@ targets:
     bringup: true
     timeout: 60
     properties:
+      release_build: "true"
       config_name: windows_android_aot_engine
 
   - name: Windows windows_host_engine
     recipe: engine_v2/engine_v2
     bringup: true
     timeout: 60
     properties:
+      release_build: "true"
       config_name: windows_host_engine
 
   - name: Windows Unopt