Do not include hidden secure cameras in camera1: getNumberOfCameras

Apps cannot connect to hidden secure cameras. Do not include them in the
number of cameras reported by camera1 api.

Bug: 141247926

Test: Without CL -> mark all cameras as hidden secure cameras;
      atest FastBasicsTest.java#testCamera1 fails
      With CL -> mark all cameras as hidden secure cameras;
      atest FastBasicsTest.java#testCamera1 passes

Test: camera CTS

Merged-In: I9d1721fd5e94fa7f692c3da52aa667ae9247d368
Change-Id: I229a336bed6b2695e16c1457cb8f74c26b07f7e8
Signed-off-by: Jayant Chowdhary <jchowdhary@google.com>
(cherry picked from commit cf935409)