Merge pull request #23504 from pritha-srivastava/wip-sts-authentication

rgw: Code for STS Authentication.

diff --cc src/common/legacy_config_opts.h
Simple merge

diff --cc src/common/options.cc
Simple merge

diff --cc src/rgw/rgw_admin.cc
Simple merge

diff --cc src/rgw/rgw_auth.cc
Simple merge

diff --cc src/rgw/rgw_auth_s3.h
Simple merge

diff --cc src/rgw/rgw_iam_policy.cc
Simple merge

diff --cc src/rgw/rgw_main.cc
Simple merge