Add API to register ProtoLog groups seperately from initialization

This allows us to have more flexibility in add groups to a tracing
instance. Particularly from places where we cannot yet initialize the
tracing instance fully like in static class initializations in Zygote.

Flag: android.tracing.imetracker_protolog
Bug: 410517697
Test: atest TracingTests
Change-Id: I4ffa468c4f7de403cc205743fe826ae7271e73a7