[release-1.24] Remove non-zero requirement on connectionPool.tcp.IdleTimeout

[istio-testing]

Manual cherrypick required.

#3455 failed to apply on top of branch "release-1.24":

Applying: Remove non-zero requirement on connectionPool.tcp.IdleTimeout
Using index info to reconstruct a base tree...
M	kubernetes/customresourcedefinitions.gen.yaml
M	networking/v1alpha3/destination_rule.pb.go
M	networking/v1alpha3/destination_rule.proto
Falling back to patching base and 3-way merge...
Auto-merging networking/v1alpha3/destination_rule.proto
Auto-merging networking/v1alpha3/destination_rule.pb.go
CONFLICT (content): Merge conflict in networking/v1alpha3/destination_rule.pb.go
Auto-merging kubernetes/customresourcedefinitions.gen.yaml
error: Failed to merge in the changes.
hint: Use 'git am --show-current-patch=diff' to see the failed patch
hint: When you have resolved this problem, run "git am --continue".
hint: If you prefer to skip this patch, run "git am --skip" instead.
hint: To restore the original branch and stop patching, run "git am --abort".
hint: Disable this message with "git config advice.mergeConflict false"
Patch failed at 0001 Remove non-zero requirement on connectionPool.tcp.IdleTimeout