Add test spec provider to test modules.

Provider added for the following test modules in this change: art_cc_test, cc_benchmark, cc_fuzz, cc_test, cc_test_host, rust_test,and rust_test_host.

Bug: 296873595
Test: Manual test
Change-Id: I815680529bcbecacb3a2bdb8f3746053afdee48c
diff --git a/rust/test.go b/rust/test.go
index 4b5296e..7ffc367 100644
--- a/rust/test.go
+++ b/rust/test.go
@@ -222,11 +222,13 @@
 	// rustTestHostMultilib load hook to set MultilibFirst for the
 	// host target.
 	android.AddLoadHook(module, rustTestHostMultilib)
+	module.testModule = true
 	return module.Init()
 }
 
 func RustTestHostFactory() android.Module {
 	module, _ := NewRustTest(android.HostSupported)
+	module.testModule = true
 	return module.Init()
 }