Update all samples to use AWS CRT-based HTTP Client

[muraria]

Using AWS CRT-based HTTP client can improve performance: https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/http-configuration-crt.html

[dmahapatro]

@ravsrin There is already an open issue here.. FYI

[dmahapatro]

Now that AWS CRT is GA. We can bump up this issue and implement it.