Add doxygen doc

Author: alinaliBQ

cpp/src/arrow/flight/sql/odbc/odbc_impl/odbc_statement.h

@@ -69,6 +69,9 @@ class ODBCStatement : public ODBCHandle<ODBCStatement> {
   void SetStmtAttr(SQLINTEGER statement_attribute, SQLPOINTER value,
                    SQLINTEGER buffer_size, bool is_unicode);
 
+  /// \brief Revert back to implicitly allocated internal descriptors.
+  /// isApd as True indicates APD descritor is to be reverted.
+  /// isApd as False indicates ARD descritor is to be reverted.
   void RevertAppDescriptor(bool is_apd);
 
   inline ODBCDescriptor* GetIRD() { return ird_.get(); }