Propagate all sanitizer flags in SDK snapshots.

liblog snapshot needs to sanitizer.address=false to avoid cycle in asan
builds. Adding that separately in library_sdk_member.go would start to
feel like whack-a-mole, so the snapshot generation is instead extended
to handle nested property structs.

This uses the BpPropertySet.AddProperty extension in
https://r.android.com/1423510, and common value optimisation now
recurses into non-anonymous structs, instead of comparing them as a
whole.

Test: m nothing
Test: `m SANITIZE_TARGET=address nothing` with prebuilts/runtime
  present in the manifest and a fresh snapshot made with this
Bug: 151303681
Change-Id: I472554117a488e6c800045cb2ed59377778571a4