Add a limit for the total amount of assets

[chrisgarrity]

ScratchJr doesn't have any limit on the number or overall size of assets that a user can create. It's possible for a child to create a project with enough sounds and characters that ScratchJr runs out of memory the next time they try to open it.

We've reduced the size of sounds, but without limiting overall size ScratchJr may still crash when there are enough assets and limited space left on the iPad. We could wait to see if the number of crash reports from users goes down to a small enough number that we're ok leaving things as they are.

Assuming we have a hard limit, what should happen?

• Does the limit apply just to sounds, or sounds and images?
• What happens when they hit the limit? Buttons to add sounds (characters) disappear? become disabled? How is that communicated to a 5-year old? A pop-up bubble that says 'size limit reached' is probably not ideal.

[deepankarmalhan]

Architecture discussion - product backlog.