Re-land: Reconcile Zygote process name code with Q release.

Re-landing due to merge from staging branch reverting fix.

Some Zygote code that was pushed to AOSP master is different from the
pushed Q release. In particular, a call to set the process name for a
Zygote child was missing, causing an app zygote test to fail.

Bug: 139535125
Test: atest android.app.cts.ServiceTest#testAppZygoteServices
Change-Id: I9cb47cea2295dd6c7df16722d3bb474185b7dc6b
Merged-In: Ice3eb966a88e6de5bc8834b60b54bcac31bf31db