Enforce IMDSv2 for EC2

[agopalun]

Use Case - Is your feature request related to a problem? Please describe.
This SCP will enforce IMDSv2 to access instance metadata for an EC2 instance

Expected Outcome - Describe the solution you'd like
SCP Policy

Describe alternatives you've considered
Detective controls using AWS Config rule "ec2-imdsv2-check"

Affected AWS resource
AWS EC2

Impact
Medium: Single feature which affects a single functionality which is optionally enabled in the AWS service

Supported material
NA

I can contribute: Yes

Additional context
NA

Pull Request number
agopalun-enforce-IMDSv2-EC2 #36