feat: Migrate vertex ai session service to use agent engine sdk

PiperOrigin-RevId: 816259798

Author: vertex-sdk-bot

vertexai/agent_engines/templates/adk.py

@@ -537,15 +537,20 @@ def set_up(self):
         if session_service_builder:
             self._tmpl_attrs["session_service"] = session_service_builder()
         elif "GOOGLE_CLOUD_AGENT_ENGINE_ID" in os.environ:
-            from google.adk.sessions.vertex_ai_session_service import (
-                VertexAiSessionService,
-            )
+            try:
+                from google.adk.sessions.vertex_ai_session_service import (
+                    VertexAiSessionService,
+                )
+
+                self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                    project=project,
+                    location=location,
+                    agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                )
+            except ImportError:
+                # TODO(ysian): Handle this via _g3 import for google3.
+                pass
 
-            self._tmpl_attrs["session_service"] = VertexAiSessionService(
-                project=project,
-                location=location,
-                agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
-            )
         else:
             self._tmpl_attrs["session_service"] = InMemorySessionService()
 

vertexai/preview/reasoning_engines/templates/adk.py

@@ -512,21 +512,26 @@ def set_up(self):
         if session_service_builder:
             self._tmpl_attrs["session_service"] = session_service_builder()
         elif "GOOGLE_CLOUD_AGENT_ENGINE_ID" in os.environ:
-            from google.adk.sessions.vertex_ai_session_service import (
-                VertexAiSessionService,
-            )
-
-            if is_version_sufficient("1.5.0"):
-                self._tmpl_attrs["session_service"] = VertexAiSessionService(
-                    project=project,
-                    location=location,
-                    agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
-                )
-            else:
-                self._tmpl_attrs["session_service"] = VertexAiSessionService(
-                    project=project,
-                    location=location,
+            try:
+                from google.adk.sessions.vertex_ai_session_service import (
+                    VertexAiSessionService,
                 )
+
+                if is_version_sufficient("1.5.0"):
+                    self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                        project=project,
+                        location=location,
+                        agent_engine_id=os.environ.get("GOOGLE_CLOUD_AGENT_ENGINE_ID"),
+                    )
+                else:
+                    self._tmpl_attrs["session_service"] = VertexAiSessionService(
+                        project=project,
+                        location=location,
+                    )
+            except ImportError:
+                # TODO(deanchen): Handle this via _g3 import for google3.
+                pass
+
         else:
             self._tmpl_attrs["session_service"] = InMemorySessionService()