[v12.x] http2: patch double-free error due to handling of rst_stream
The PR patches the double-free error due to handling of
RST_STREAM
frame with cancel code.
The previous PR(#39423) causes build failure with
v12.x-staging
branch since the interfaces to check the
session flags changes. The changes backport APIs to
check the status flag of Http2Session
as well.
Ref: #39423 Fixes: #38964