Removing get_metric_name from common/metrics/src/lib.rs
Removing get_metric_name from common/metrics/src/lib.rs

Closes: #4219
Approved by: bmwill

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