Restore reverted CleanSpec

Ica006a007d112c232311435aaac0c0e476232b67 added a clean step that was
reverted in I0ce3ad70c73ff997aacaf411b0b5dc73760e7f91.  Reverting
a clean step could cause a future clean step to be skipped, because
Make only tracks how many clean steps have been run out of each
CleanSpec.mk file.  Add back the reverted clean step.

Bug: 119412419
Test: none
Change-Id: I11fe12d7c3526ccc21f468b350b4288cb55a9447