[#12293] YSQL: Adjust default value in copy test

Summary:
In D16752 we changed the default value of ROWS_PER_TRANSACTION.
Here we fix the test to adjust the value of rows per transaction accordingly.

Test Plan: `ybd --java-test org.yb.pgsql.TestBatchCopyFrom`

Reviewers: smishra, rthallam

Reviewed By: rthallam

Subscribers: yql

Differential Revision: https://phabricator.dev.yugabyte.com/D16755

java/yb-pgsql/src/test/java/org/yb/pgsql/TestBatchCopyFrom.java

@@ -49,7 +49,7 @@ public class TestBatchCopyFrom extends BasePgSQLTest {
       "violates foreign key constraint";
   private static final String BATCH_TXN_SESSION_VARIABLE_NAME =
       "yb_default_copy_from_rows_per_transaction";
-  private static final int BATCH_TXN_SESSION_VARIABLE_DEFAULT_ROWS = 1000;
+  private static final int BATCH_TXN_SESSION_VARIABLE_DEFAULT_ROWS = 20000;
   private static final String DISABLE_TXN_WRITES_SESSION_VARIABLE_NAME =
       "yb_disable_transactional_writes";
   private static final String YB_ENABLE_UPSERT_MODE_VARIABLE_NAME =
@@ -479,7 +479,7 @@ public void testBatchTxnSessionVariable() throws Exception {
           INVALID_COPY_INPUT_ERROR_MSG);
       assertOneRow(statement, "SELECT COUNT(*) FROM " + tableName, expectedCopiedLines);
 
-      // reset session variable (attempt to copy default of 1000 rows)
+      // reset session variable
       statement.execute("RESET " + BATCH_TXN_SESSION_VARIABLE_NAME);
       assertOneRow(statement, "SHOW " + BATCH_TXN_SESSION_VARIABLE_NAME,
           String.valueOf(BATCH_TXN_SESSION_VARIABLE_DEFAULT_ROWS));