[jsk_fetch_startup] update time_signal schedule and speak more info

[knorth55]

this PR changes time_signal schedule and change the speaking info.

[tkmtnt7000]

Nice change !!
Wait for fixing CI.

[k-okada]

Does two robots speak same comment at same time?
I think the method to coordinates who to notify people around the robot would be very interesting topic for those who are interested in robot comunicate each other (@tkmtnt7000 )
For example, when time is approaching

• observe people and robot, and understand who is talking to whom
• if no one is talking, then start talking?
• if someint is talking, let them to understand that I am start talking?
  etc...

[tkmtnt7000]

Does two robots speak same comment at same time?

Yes. Fetch15 and Fetch1075 speak the same comment at the same time.

For example, when time is approaching

observe people and robot, and understand who is talking to whom
if no one is talking, then start talking?
if someint is talking, let them to understand that I am start talking?
etc...

I'll try some methods. I think two robots do not always have to speak same comments.