Fix potential FD leak with PhantomProcessRecord bookkeeping

We're tracking the phantom processes with the combination of
its process name and pid/uid, while if the process name changes
it'll be removed from the internal bookkeping, we should close
the FD to that process upon then.

Bug: 194146206
Test: atest AppChildProcessTest
Test: atest CtsAppTestCases:ActivityManagerTest
Change-Id: I62064afe55aa8bc51a2d523bc5d8fe6e97f171a8