discuss: minikube wait for default service accont ?

[medyagh]

as part of this PR #6999 to close #6997

I added wait for default service account to be created before the integeration tests apply yaml files.
at first I wanted to add that to minikube itself but that added 30 seconds to minikube start on my machine. and this would add very little value to 90% of the people.
even in our high stress integeration test it is a flake behavior, that sometimes we get this errr described here #6997

we could do one these, so neither the kabab be burnt nor the skewer. (persian slang) :

option 1 switch default behaviour

we can make the current wait=true behaviour to be called wait=false (do current wait behaviour even if user dosnt wanna wait)
and make wait=false the default behavior
and then for wait=true we add waiting for default service account.
that would make minikube more usable in testing environments.

option 2 add a new flag, get list of componenets to wait for

we add another flag, that gets a list of things that user wants us to wait for
--wait-for: [comp1, comp2, comp3]

like
--wait-for=apiserver,default-service-account
--wait-for=all

option 3 change the current flag from boolean to list

--wait
with a default value of the current things we wait for
apiserver,.systempods...

and we should handle logic that if user provided true or false, we should translate that for backward comaptibility

but if user wanted to they could add more to the list
--wait=all
ot
--wait=apiserver,systempods,default_sa ...

This seems to be covering up an actual flaw that users can face. Shouldn't the start command wait for this?

Originally posted by @tstromberg in https://github.com/kubernetes/minikube/pull/6999/files