[FIX] sap.m.SearchField: active state is not shown in Firefox

- active state of the "search" and "reset" buttons is not 
  displayed in Firefox


Change-Id: Iaeca165b27a6c503a846a554569dc8d8eddc1352
CSS: 0120031469 0000653446 2014
Merge "[FIX] sap.m.SearchField: active state is not shown in Firefox"