feat(ec2): Add VPC endpoint for RDS (#12497)

Adds VPC endpoint support for RDS. Fixes #12402

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*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

Author: bcelenza

packages/@aws-cdk/aws-ec2/lib/vpc-endpoint.ts

@@ -287,6 +287,7 @@ export class InterfaceVpcEndpointAwsService implements IInterfaceVpcEndpointServ
   public static readonly KMS = new InterfaceVpcEndpointAwsService('kms');
   public static readonly CLOUDWATCH_LOGS = new InterfaceVpcEndpointAwsService('logs');
   public static readonly CLOUDWATCH = new InterfaceVpcEndpointAwsService('monitoring');
+  public static readonly RDS = new InterfaceVpcEndpointAwsService('rds');
   public static readonly SAGEMAKER_API = new InterfaceVpcEndpointAwsService('sagemaker.api');
   public static readonly SAGEMAKER_RUNTIME = new InterfaceVpcEndpointAwsService('sagemaker.runtime');
   public static readonly SAGEMAKER_RUNTIME_FIPS = new InterfaceVpcEndpointAwsService('sagemaker.runtime-fips');

packages/@aws-cdk/aws-ec2/package.json

@@ -233,6 +233,7 @@
       "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.KINESIS_STREAMS",
       "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.KINESIS_FIREHOSE",
       "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.KMS",
+      "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.RDS",
       "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.SAGEMAKER_API",
       "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.SAGEMAKER_NOTEBOOK",
       "docs-public-apis:@aws-cdk/aws-ec2.InterfaceVpcEndpointAwsService.SAGEMAKER_RUNTIME",