[INTERNAL] Inappropriate style for sap.ui.unified.Shell removed from
sap.m.Button less file

Change-Id: Ibdd2cfee84e3750fed4e6557e52341e2b7d5dde9
BCP: 1472015123
CR-Id: 012006153200015519122014
Merge "[INTERNAL] Inappropriate style for sap.ui.unified.Shell removed from sap.m.Button less file" into rel-1.26