Revert to using the app guid as the event guid after a purge

- The SecureRandom uuid was being run too early so was giving every event the same guid!
- The old "hack" of using the app's guid ensures that every event gets a unique guid

Signed-off-by: Kai Zhang <kaizhang@cn.ibm.com>
Work around pg vs mysql inconsistency

Creating an App in a STARTED state on mysql and sqlite result in an AppUsageEvent being created but on pg there is no event

[#68851718]

Signed-off-by: Kai Zhang <kaizhang@cn.ibm.com>
Temporarily disable specs, they are not reliable on mysql

We retrofitted these yesterday, the functionality under test is already exercised by controller specs
and we will re-enabled these specs as part of [#68852028]

Signed-off-by: Kai Zhang <kaizhang@cn.ibm.com>