[INTERNAL][FIX] sap.m.MultiComboBox: Change arrow background color when open in phone

Change-Id: I3337d454a0526ef4262812d23d140cc6167338c7
(cherry picked from commit 38365d2227c7db3a1bc724658fe5aa6aca84a847)
CR-Id: 012003146900009007982014
Merge "[INTERNAL][FIX] sap.m.MultiComboBox: Change arrow background color when open in phone" into rel-1.26