The logic was incorrect in the presence of multiple paths
(cluster installs) or multiple instruction sets (multi arch)
because of an early return in the case of sucessful dexopt.
- Rewrite this logic to make it (hopefully) clearer.
- Fix a related bug in getAppDexInstructionSets.
- Add instruction set to the dexopt logs.
bug: 16013931
Change-Id: I18c9755583f0a6f8be70469ec2062269564f0f41