[ITS] handle non-primary cameras in test_zoom and test_preview_zoom

test_zoom uses JCA, which uses primary cameras in the front and rear facing only. It should therefore SKIP for other cameras.
test_preview_zoom should only check for a camera switch if the camera is a primary camera.

Flag: TEST_ONLY
Bug: 404463059
Test: ran test_zoom and test_preview_zoom
Change-Id: I43009c663c24c66a193c1ac2a631a6d62d5d6d04