Introducing BuildBuddy v2

BuildBuddy v2 has been released to improve developer productivity by optimizing the performance of a remote build execution system. The new version includes significant improvements in caching, sandboxing, and execution, reducing clean, uncached build times for TensorFlow from 28 minutes to just 3.47 minutes. BuildBuddy v2 also introduces three new features that give users more control over the trade-offs between hermeticity and performance. Additionally, other improvements have been made in query performance, UI display, reliability, and default Xcode version configuration options.