sql: fix crdb_internal statment_activity and transaction_activity tables

The virtual table is selecting the wrong columns from the system
table causing it to fail. This fixes the column names and adds tests.

Release note: None
Part of #98882
Epic: None

pkg/sql/opt/exec/execbuilder/testdata/observability

@@ -12,6 +12,12 @@ INSERT INTO system.users VALUES ('node', NULL, true, 3)
 statement ok
 GRANT node TO root
 
+statement ok
+SELECT * FROM crdb_internal.transaction_activity
+
+statement ok
+SELECT * FROM crdb_internal.statement_activity
+
 # Upsert all transaction_activity
 query T retry
 EXPLAIN (VERBOSE) UPSERT INTO system.public.transaction_activity

pkg/sql/sql_activity_update_job_test.go

@@ -81,6 +81,16 @@ func TestSqlActivityUpdateJob(t *testing.T) {
 	require.NoError(t, err)
 	require.Equal(t, 0, count, "statement_statistics: expect:0, actual:%d", count)
 
+	row = db.QueryRowContext(ctx, "SELECT count_rows() FROM crdb_internal.transaction_activity")
+	err = row.Scan(&count)
+	require.NoError(t, err)
+	require.Equal(t, 0, count, "crdb_internal.transaction_activity: expect:0, actual:%d", count)
+
+	row = db.QueryRowContext(ctx, "SELECT count_rows() FROM crdb_internal.statement_activity")
+	err = row.Scan(&count)
+	require.NoError(t, err)
+	require.Equal(t, 0, count, "crdb_internal.statement_activity: expect:0, actual:%d", count)
+
 	execCfg := srv.ExecutorConfig().(ExecutorConfig)
 	st := cluster.MakeTestingClusterSettings()
 	updater := newSqlActivityUpdater(st, execCfg.InternalDB)
@@ -164,6 +174,18 @@ func TestSqlActivityUpdateJob(t *testing.T) {
 	err = row.Scan(&count)
 	require.NoError(t, err)
 	require.Equal(t, count, 1, "statement_activity after transfer: expect:1, actual:%d", count)
+
+	row = db.QueryRowContext(ctx, "SELECT count_rows() "+
+		"FROM crdb_internal.transaction_activity WHERE app_name = $1", appName)
+	err = row.Scan(&count)
+	require.NoError(t, err)
+	require.Equal(t, count, 1, "transaction_activity after transfer: expect:1, actual:%d", count)
+
+	row = db.QueryRowContext(ctx, "SELECT count_rows() "+
+		"FROM crdb_internal.statement_activity WHERE app_name = $1", appName)
+	err = row.Scan(&count)
+	require.NoError(t, err)
+	require.Equal(t, count, 1, "statement_activity after transfer: expect:1, actual:%d", count)
 }
 
 // TestSqlActivityUpdateJob verifies that the