NextJS: Use correct default port number 3000

Change-Id: Iba055accf2f08a167d03f036df20bf9a9674e88d
diff --git a/charts/app-runner/values.yaml b/charts/app-runner/values.yaml
index 795f2c0..aaf8592 100644
--- a/charts/app-runner/values.yaml
+++ b/charts/app-runner/values.yaml
@@ -13,3 +13,4 @@
 volumes: []
 runtimeClassName: ""
 extraContainers: []
+apiPort: 3000