Reuse the client, rather than create a new client

[zhangyuezhong]

amazon-connect-realtime-transcription/src/main/java/com/amazonaws/kvstranscribestreaming/KVSUtils.java

Line 193 in 556a5ec

AmazonKinesisVideoMediaClientBuilder amazonKinesisVideoMediaClientBuilder = AmazonKinesisVideoMediaClientBuilder.standard()

the code at here creates AmazonKinesisVideoMedia client and AmazonKinesisVideo client every time call.

i'm running the code in EC2, how can we re-use these two client, rather than create them every time. the underlying http client will be created as well.