THIRD AMENDED AND RESTATED SENIOR SECURED CREDIT AGREEMENT Dated as of December 15, 2020 among APARTMENT INCOME REIT CORP., AIR REIT SUB 1, LLC, AIR REIT SUB 2, LLC, AIMCO PROPERTIES, L.P., and AIMCO/BETHESDA HOLDINGS, INC., as the Borrowers, KEYBANK...