Repro steps:
1. Create an empty system
2. Add a Set Age attribute in Initialize
3. Select Update and observe that the 'Age Particles' option is not visible.

Expected outcome:
- Age Particles to be visible

Notes:
- 'Age Particles' does appear if lifetime is added or if age is used within the same graph. However, if the age attribute is used in a GPU Event (attached video), then the user doesn't have control over the aging of the particles. A user also has to use the age attribute before they can chose whether they want the particles to age or not.
- Suggest showing 'Age Particles' if the Age attribute is added (even if it is just in initialize and not used anywhere), and only removing the extra aging calculation if the age attribute is not used in the current system or any related GPU-event system.