test: fixed failed system test cases (#1810)

Fixes #1809

Author: surbhigarg92

system-test/spanner.ts

@@ -3759,10 +3759,11 @@ describe('Spanner', () => {
  const GOOGLE_SQL_EXPECTED_ROW = extend(true, {}, GOOGLE_SQL_INSERT_ROW);
  const POSTGRESQL_EXPECTED_ROW = extend(true, {}, POSTGRESQL_INSERT_ROW);
 
- before(() => {
- return googleSqlTable.insert(GOOGLE_SQL_INSERT_ROW).then(() => {
- postgreSqlTable.insert(POSTGRESQL_INSERT_ROW);
- });
+ before(async () => {
+ await googleSqlTable.insert(GOOGLE_SQL_INSERT_ROW);
+ if (!IS_EMULATOR_ENABLED) {
+ await postgreSqlTable.insert(POSTGRESQL_INSERT_ROW);
+ }
  });
 
  const queryCallbackMode = (done, database, query, EXPECTED_ROW) => {