MINOR: Modify Connect service's startup timeout to be passed via the init (#5882)
MINOR: Modify Connect service's startup timeout to be passed via the init (#5882)

Currently, the startup timeout is hardcoded to be 60 seconds in Connect's test service. Modifying it to be passable via init. This can safely be backported as well.

Reviewers: Randall Hauch <9972a9c98f4ad2f4c07879e61ff8ef543017832b@gmail.com>, Jason Gustafson <jason@confluent.io>
lindong28/kafka,sslavic/kafka,noslowerdna/kafka,noslowerdna/kafka,sslavic/kafka,KevinLiLu/kafka,gf53520/kafka,Chasego/kafka,KevinLiLu/kafka,TiVo/kafka,noslowerdna/kafka,TiVo/kafka,apache/kafka,gf53520/kafka,apache/kafka,lindong28/kafka,guozhangwang/kafka,sslavic/kafka,guozhangwang/kafka,gf53520/kafka,lindong28/kafka,KevinLiLu/kafka,lindong28/kafka,TiVo/kafka,KevinLiLu/kafka,Chasego/kafka,sslavic/kafka,Chasego/kafka,Chasego/kafka,apache/kafka,guozhangwang/kafka,apache/kafka,TiVo/kafka,guozhangwang/kafka,gf53520/kafka,noslowerdna/kafka