Skip test_stamp_pattern until bug 1664793 is fixed

test_stamp_pattern fails for some backends, and
I79ef5b3751747755fc71793f4701e9c886a3e4ff is trying to fix it.

This is to skip test_stamp_pattern until bug 1664793 is fixed.

Change-Id: I79c146f7f5db230097fd30e0ec9f4530337913d6
1 file changed