Otapreopt: Add non-profile fallback

Slightly refactor compilation flow. Add a fallback option: if the
compilation fails and was profile-guided, attempt a non-profile-
guided compilation. This makes A/B OTA more robust to profile
format changes.

Bug: 37256688
Test: m
Test: manual OTA N -> O
Change-Id: I20c4b44a87c0f7faa8920abdae01e39379405eca