Fixup App Compaction CL nits.

A couple of nits to cleanup from change I71fffc52a232cd5608742d9f36965a4de6494b56

 - remove unused method
 - remove unnecessary null check.

BUG: 128427978
Test: atest FrameworksMockingServicesTests:AppCompactorTest
Change-Id: I363c57fc78529207585f5d1e004770d967ce87b9
1 file changed