[SOONG] Not auto-generate test config if test_suite is cts

Current soong use source code's under cts as the rule for judgement.
Should change to use test_suites define instead.

Bug: 124313692
Test: m hello_world_test, make sure test config be auog-enerated.
      Modified platform_testing/tests/example/native/Android.bp
      m hello_world_test, make sure test config not be auto-generatetd.

Change-Id: I1bc5216f73329d2a82d9ff29ccbede436dd2976c