Add basic test coverage for sysystemfeatures-gen args

Test the following scenarios:
 * An invalid feature version is provided
 * An "android"-prefixed raw feature name is provided

In the case of the latter, any "android"-namespaced feature
must come by way of an existing PackagerManager.FEATURE_ definition.

Bug: 376463304
Test: atest systemfeatures-gen-tests
Flag: build.RELEASE_USE_SYSTEM_FEATURE_BUILD_FLAGS
Change-Id: If74899b5ebeeee7db0e9b2c8162076f8edd4381f
diff --git a/tools/systemfeatures/Android.bp b/tools/systemfeatures/Android.bp
index 590f719..e6d0a3d 100644
--- a/tools/systemfeatures/Android.bp
+++ b/tools/systemfeatures/Android.bp
@@ -58,6 +58,7 @@
         "junit",
         "objenesis",
         "mockito",
+        "systemfeatures-gen-lib",
         "truth",
     ],
 }