Atest: recognize modern robo test as deviceless

Previously Atest cannot distinguish between robolectric test and device
tests, so that the get_supported_exec_mode() is not very accurate. This
CL ensure Atest recognize modern robolectric test as deviceless test.

BUG: 215660415

Test: $ atest-src SettingsRoboTests HelloWorldTests -c
will see "There are host-only and device-only tests in command."

$ atest-src WallPaperPicker2RoboTests WallpaperPicker2Tests
will keep building step.

Change-Id: Ia1511e5f3bb27c7b6481990bb92a2d8ba38fc442
4 files changed