Summary:
asan_symbolize.py is not compatible with python3. Also make it
consistent with public CI, which doesn't use asan_symbolize.py
And update coverage_test.sh to use python3.
Pull Request resolved: https://github.com/facebook/rocksdb/pull/8737
Test Plan: CI
Reviewed By: pdillinger
Differential Revision: D30702430
Pulled By: jay-zhuang
fbshipit-source-id: ef09947b1232294d31b09a855c2f0ce149097dd9