[INTERNAL][FIX] sap.m.SearchField: Fixed button highlight on mobile

Fix for the problem with highlight of the button remaining even after
the press was ended. Had to add platform-specific selectors to cover
Android/iOS/Windows7/BB. Now the button is highlighted only during
press.

Change-Id: I60ce72981bce6e4665002e5c4d755dc83b0f7340
Merge "[INTERNAL][FIX] sap.m.SearchField: Fixed button highlight on mobile"