Ignore tests for devices without valid camera flash

The checking for valid camera flash is incorrect. We should make sure there's at least one valid camera available before running the tests.

Bug: 299560792
Test: abtd run https://android-build.corp.google.com/builds/abtd/run/L49500000963428162
Change-Id: I7c502780c9d123ee319c8c0fd91cfb29e945d3f1