Update phone gesture nav test in NavButtonLayoutFactoryTest

I think the test was written in the first version of NavButtonLayoutFactoryTest where phone gesture nav layouter didn't exist (verified with the revision history), hence updating the logic here

Bug: 324989451
Test atest NavButtonLayoutFactoryTest

Change-Id: I325a5d47db86add8d094e61b1de923f50a2db309
1 file changed