[cluster-test] Install awscli
[cluster-test] Install awscli

One of previous commits removed installing awscli from cluster-test runner.
We need it actually, so putting it back

Since we have single ec2_user_data.sh for all instances, this will mean installing awscli on all hosts, which should not be big deal(it was there before)

Closes: #1969
Approved by: sausagee

libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,libra/libra,aptos-labs/aptos-core,libra/libra,libra/libra,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core,aptos-labs/aptos-core