Add input tests to continuous testing

All of libinput and inputflinger native tests will now be run
continuously.

Test: "m -j continuous_native_tests" followed by "unzip -l
out/target/product/taimen/obj/PACKAGING/
continuous_native_tests_intermediates/continuous_native_tests.zip
| grep input"
Bug: 68865272

Change-Id: I6838f49a8e7d271de4b592d3f5f4f67e497ba0f9