Reland: [Impeller] add a configuration option that allows defering all PSO construction until needed. (#165622)

The cost of bootstapping the initial PSOs can regress cold startup time
for customer money. As an experiment, attempt to defer PSO construction
to skia like.

---------

Co-authored-by: Aaron Clarke <aaclarke@google.com>
Co-authored-by: gaaclarke <30870216+gaaclarke@users.noreply.github.com>

.ci.yaml

@@ -2730,6 +2730,17 @@ targets:
         ["devicelab", "android", "linux"]
       task_name: flutter_gallery__start_up
 
+  # linux mokey benchmark
+  - name: Linux_mokey flutter_gallery_lazy__start_up
+    recipe: devicelab/devicelab_drone
+    presubmit: false
+    bringup: true
+    timeout: 60
+    properties:
+      tags: >
+        ["devicelab", "android", "linux"]
+      task_name: flutter_gallery_lazy__start_up
+
   # linux mokey benchmark
   - name: Linux_mokey flutter_gallery__start_up_delayed
     recipe: devicelab/devicelab_drone