Revert STS changes from 1.4 branch#175

Closed

duderino wants to merge 8 commits intoistio:release-1.4from

duderino:jblatt_revert_sts

Commits on Mar 3, 2020

Revert "fix opencensus tracer (#155)"
duderino
committed
Revert "Add x-goog-user-proj header for sts credential (#152)"
duderino
committed
Revert "Update GrpcService to add StsService. (#411)"
duderino
committed
Revert "fix tracer ssl credential (#151)"
duderino
committed
Revert "remove url validation as it is not implemented"
duderino
committed
Revert "Use gRPC Security Token Service (STS) to get call credentials (#9101)"
duderino
committed
Revert "[release-1.4] Use sts for call credential when STS_PORT is provided in node metadata #144 (#148)"
duderino
committed
Revert "Upgrade gRPC to 1.25 which has gRPC STS feature (#145)"
duderino
committed