Make remaining objC jobs compatible with kokoro monterey workers and
prepare for boringssl upgrade.
The changes here are taken from https://github.com/grpc/grpc/pull/32357,
but they should be merged in a separate PR
(we need the changes to be able to upgrade to monterey anyway and
there's no reason to make the boringssl upgrade PR more complicated by
bundling more fixes into it).
I've checked that the grpc_basictests_objc_examples and
grpc_ios_binary_size are green if switched to monterey.
Unfortunately it's hard to make grpc_basictests_objc_examples pass on
both monterey and mojave, so I suggest merging this PR at the same time
as CL to upgrade the kokoro jobs to monterey.
- that way both PR and continuous runs will remain green
- older branches would need a backport anyway
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Co-authored-by: Hannah Shi <hannahshisfb@gmail.com>
Jan Tattermusch
740932c899