Modify GC Delay to include subsequent launches. (fix)

Application launches for apps like GMS Music
and Maps lead to explicit GC's due to Binder
activity in the SystemServer. This change
allows delaying the GC for 3 seconds after
the application is launched. Subsequent launches
or previously killed applications with existing
activity records are also now covered.

Change-Id: I1a915d5b8a8bf752991a429328fe398ff4f1eae2