AN ACT AMENDING SECTION 13-A OF REPUBLIC ACT 8291 (GSIS ACT OF 1997) BY PRESCRIBING OTHER CONDITIONS FOR ENTITLEMENT TO THE RETIREMENT BENEFITS, UNDER SECTION 13 OF THE SAME ACT, FOR GOVERNMENT EMPLOYEES OR OFFICIALS BEING PHASED OUT AND/OR NOT RETAINED BY HIS OFFICE/BUREAU/CORPORATION/ DUE TO PRIVATIZING/ABOLISHING HIS OFFICE