Gallery2: Change method for Filter compare

The method of 'same' compare the class between two FilterRepresentation,
and the method of 'equal' compare everything between two FilterRepresentation.
Since two border have the same class of 'ImageFilterBorder', they are
considered no diff in method of 'same'.

Change the method 'same' to 'equal'.

CRs-Fixed: 759358

Change-Id: I80dda9295555181d70c90bd893ea2c3efb7d41e3