{CODEOWNERS} Add CODEOWNERS for botservice (#21968)
{CODEOWNERS} Add CODEOWNERS for botservice (#21968)

Signed-off-by: jiaxuwu2021 <0b6909fd630a6c85815e6e6f54f48969fc336ee5@microsoft.com>
yugangw-msft/azure-cli,yugangw-msft/azure-cli,yugangw-msft/azure-cli,yugangw-msft/azure-cli,yugangw-msft/azure-cli,yugangw-msft/azure-cli