Modify agressive service restart timer

[gregorybel]

use Missed Reading timer instead of a fix 5min timer.
Like this each has possibility to use a different timer.
I suggest using 6min for example.
Tested successfully.

PS: sorry PR is not so clean due to old commits.... :-)

[gregorybel]

@jamorham any questions or remarks?

[jamorham]

This looks like it will modify more than the aggressive restart timer due to the way the missed readings service is structured.

What is the purpose of this PR, what issue is it designed to resolve or feature to implement?

[gregorybel]

I see several issues:

• user has no way to configure timer by itself, timer is fixed at 5min
• most of the time, CGM send data every 5min, thus another timer value should be used, 6min for example

I thought combining both restart and missed reading would make sence.

@jamorham which issue do you see doing this?