Fix dismiss target magnetization

After the dismiss target is hidden, its scale values were not reset. That caused screen location coordinates to be miscalculated which resulted in magnetization to a bad location.

This also fixes the size of the dismiss view when dragging the second time.

Demo: http://recall/-/bJtug1HhvXkkeA4MQvIaiP/fLb6dPo9ftviyHEmZFirMA

Fixes: 308734724
Test: Manual
       - Add bubble and drag it to dismiss
       - Repeat
       - Observe that bubble is magnetized correctly
Change-Id: I7e9854acb700e468b6fa7fd1ebde5a0f83b44025