message: Update getRef to accomodate whole summary upload.
diff: @@ -253,12 +253,11 @@ export class SummaryWriter implements ISummaryWriter {
  op.additionalContent,
  JSON.stringify(checkpoint));
  - // Fetch the last commit and summary tree. Create new trees with logTail and serviceProtocol.
  - const lastCommit = await this.summaryStorage.getCommit(existingRef.object.sha);
  -
  if (this.enableWholeSummaryUpload) {
  - await this.createWholeServiceSummary(lastCommit.sha, logTailEntries, serviceProtocolEntries);
  + await this.createWholeServiceSummary(existingRef.object.sha, logTailEntries, serviceProtocolEntries);
  } else {
  + // Fetch the last commit and summary tree. Create new trees with logTail and serviceProtocol.
  + const lastCommit = await this.summaryStorage.getCommit(existingRef.object.sha);
  const [logTailTree, serviceProtocolTree, lastSummaryTree] = await Promise.all([
  this.summaryStorage.createTree({ entries: logTailEntries }),
  this.summaryStorage.createTree({ entries: serviceProtocolEntries }),
  