Remove unstarted freeze surface before starting new freeze

Before, when freeze is calling again before the previous one starts
animation, the old one will never be removed.

Fix: 203491879
Test: atest WmTests:WindowContainerTests
      #testRemoveUnstartedFreezeSurfaceWhenFreezeAgain
Change-Id: If2ca5154f7c4420f43ba3964bcd1067b6e376417