[Finishes 66739328]: Success criteria for level 7

Linked to https://github.com/code-dot-org/dashboard/pull/316

Added a finish target for level 7. Added a new failOnBallExit param. Added a timeout for level 7.

Increased collision threshold to make it easier to hit ball targets.

Increased idealBlocks to allow users to play sounds (we may want to change to infinite like flappy).