tests: enable confidential_guest setting for coco

This commit updates the `tests_common.sh` script
to enable the `confidential_guest`
setting for the coco tests in the Kubernetes
integration tests.

Signed-off-by: Archana Choudhary <archana1@microsoft.com>

src/tools/genpolicy/genpolicy-settings.json

@@ -165,8 +165,8 @@
         },
         "confidential_emptyDir": {
             "mount_type": "local",
-            "mount_source": "^$(cpath)/$(sandbox-id)/local/",
-            "mount_point": "^$(cpath)/$(sandbox-id)/local/",
+            "mount_source": "^$(cpath)/$(sandbox-id)/rootfs/local/",
+            "mount_point": "^$(cpath)/$(sandbox-id)/rootfs/local/",
             "driver": "local",
             "source": "local",
             "fstype": "local",
@@ -375,4 +375,4 @@
         "UpdateEphemeralMountsRequest": false,
         "WriteStreamRequest": false
     }
-}
+}