Cloud SQL for MySQL managed buffer pool is now generally available (GA)

## Feature Feature Cloud SQL for MySQL [managed buffer pool](https://cloud.google.com/sql/docs/mysql/optimize-high-memory-usage#enable-managed-buffer-pool)is now generally available ([GA](https://cloud.google.com/products/#product-launch-stages)). Managed buffer pool helps you avoid out-of-memory events (OOMs) on your Cloud SQL instance by reducing `innodb_buffer_pool_size` when memory usage is high.