Changelog:
============
-Enable affinity_session_drain_test for cpp
-rm invalid assert
-Make C++ xDS Interop Client and Server Responsive to SIGTERM
-Fix readme
-Backport #35973: Make Bazel requirements installable directly via pip
Signed-off-by: Wang Mingyu <wangmy@fujitsu.com>
Signed-off-by: Khem Raj <raj.khem@gmail.com>
