Close unused Image before acquire new one

Fix IllegalStateException: maxImages (30) has already been acquired, call #close before acquiring more.
Before onImageRequestCompleted, onImageAvailable may be called multiple times, with only the last one being used. And acquireLatestImage has limitations, so it is necessary to close unused images.

Change-Id: I2cc1da31596d2458b31d14340b151ac0d8311ca7