Chore: [AEA-6258] - Set the defaultValue to default to undefined (#645)

## Summary

- Routine Change

Author: wildjames

packages/cdkConstructs/src/config/index.ts

@@ -5,7 +5,7 @@ import {StandardStackProps} from "../apps/createApp"
 export function getConfigFromEnvVar(
   varName: string,
   prefix: string = "CDK_CONFIG_",
-  defaultValue: string | undefined
+  defaultValue: string | undefined = undefined
 ): string {
   const value = process.env[prefix + varName]
   if (!value) {
@@ -20,7 +20,7 @@ export function getConfigFromEnvVar(
 export function getBooleanConfigFromEnvVar(
   varName: string,
   prefix: string = "CDK_CONFIG_",
-  defaultValue: string | undefined
+  defaultValue: string | undefined = undefined
 ): boolean {
   const value = getConfigFromEnvVar(varName, prefix, defaultValue)
   return value.toLowerCase().trim() === "true"
@@ -29,7 +29,7 @@ export function getBooleanConfigFromEnvVar(
 export function getNumberConfigFromEnvVar(
   varName: string,
   prefix: string = "CDK_CONFIG_",
-  defaultValue: string | undefined
+  defaultValue: string | undefined = undefined
 ): number {
   const value = getConfigFromEnvVar(varName, prefix, defaultValue)
   return Number(value)