Resolve once a transaction commits, or reject if it errors or aborts.
A write is durable at commit, not at request success — quota pressure and
storage eviction abort a transaction whose every request already succeeded.
Reads may resolve on promisifyRequest; writes must await this.
Resolve once a transaction commits, or reject if it errors or aborts.
A write is durable at commit, not at request success — quota pressure and storage eviction abort a transaction whose every request already succeeded. Reads may resolve on promisifyRequest; writes must await this.