migrate hot reload benchmark to the new devicelab framework (#5878)

dev/devicelab/manifest.yaml

diff --git a/dev/devicelab/manifest.yaml b/dev/devicelab/manifest.yaml
index 21afb54..80afa85 100644
--- a/dev/devicelab/manifest.yaml
+++ b/dev/devicelab/manifest.yaml
@@ -103,6 +103,12 @@
     stage: devicelab
     required_agent_capabilities: ["has-android-device"]
 
+  hot_mode_dev_cycle__benchmark:
+    description: >
+      Measures the performance of Dart VM hot patching feature.
+    stage: devicelab
+    required_agent_capabilities: ["has-android-device"]
+
 
   # iOS on-device tests