I don't believe there are any specific rules relating to Drones / Lockdown however to play it safe:
Find a place where others are bending the rules. Large Skate parks, or find someplace where there is no one else. That way, most people won't care about your drone. I am not suggesting rule-breaking but I also live in Victoria (Glen Waverley) and people are increasingly doing their "own thing" but applying common sense and sticking to the bulk of the rules (social distancing, masks, etc). I went out flying yesterday to do some commercial stuff with a pro aerial cinematographer and he hasn't flown since Feb. only because he doesn't want the hassle of the drone objectors having another excuse. Fly somewhere where there are few people and stick to the normal safety rules and you should be ok. If anyone approaches you, just say you are like everyone else and trying to deal with the whole situation as best you can. I believe most people will be sympathetic.
As for the cops, just stay away from their "Grand Final weekend only" spy drones and again if asked, put it down to exercise for mental health or commercial operator keeping up-skills.
If fined, be like the other 90 odd % of people who have not paid. All lockdown fines are now being reviewed as they have been found to be potentially illegal (having been issued under a law which itself is now being investigated as potentially illegally imposed).
Trying to walk the line between what is press released and what is actually happening so please don't think I am being judgemental one way or the other. Happy flying