No way to refresh trusted apps current application keys

The trusted apps current application keys are stored in a lazy reference in DefaultCurrentApplicationFactory. They are not reset by a cache cleared event, and there is no way to refresh the keys without restarting JIRA. This causes a problem in JIRA Studio where we have often needed to refresh keys. Use cases as follows:

• Security breach requires resetting of all secrets
• A customers import contains their old keys, which poses security risks to both Atlassian and the customer
• Studio changes the way keys are managed to a shared key between all apps

Since the keys are stored in ApplicationProperties, it is simple for Studio to set/change them, however, those changes won't be picked up until JIRA has restarted. This request is specifically for a mechanism to clear the cache without restarting JIRA.