fix: replace current_database() = '..' clauses (#2788)

Replace `current_database() = '...' clauses in JDBC system queries.
This is generated by (among others) Liquibase.

Fixes the build error in #2752

src/main/java/com/google/cloud/spanner/pgadapter/statements/JdbcMetadataStatementHelper.java

@@ -251,6 +251,7 @@ private static String replaceGetTablesQuery(String sql, String replacedSql) {
     }
     replacedSql += " WHERE TRUE " + sql.substring(startIndex);
     return replacedSql
+        .replaceFirst(" AND current_database\\(\\) = '.*?'", "")
         .replace(" AND n.nspname LIKE ", " AND TABLE_SCHEMA LIKE ")
         .replace(" AND c.relname LIKE ", " AND TABLE_NAME LIKE ")
         .replace(