Package robolectric tests for tradefed

Package a slightly modified copy of the robolectric tests with
the dependencies statically included into the testcases directory
and into a robolectric-tests.zip.

Test: m robolectric-tests
Change-Id: I73f51727695136d2a849d36af1683e93f7e156a3

android/Android.bp

@@ -45,6 +45,7 @@ bootstrap_go_package {
         "sdk.go",
         "singleton.go",
         "soong_config_modules.go",
+        "test_suites.go",
         "testing.go",
         "util.go",
         "variable.go",