Make TestContext.RegisterModuleType take an android.ModuleFactory

Avoid having to pass ModuleFactoryAdaptor to every call to
RegisterModuleType in a test by wrapping RegisterModuleType.

Test: all soong tests
Change-Id: If8847d16487de0479cc3020b728256922b3cadba
diff --git a/cc/test_data_test.go b/cc/test_data_test.go
index 21ea765..962ff26 100644
--- a/cc/test_data_test.go
+++ b/cc/test_data_test.go
@@ -126,10 +126,8 @@
 				"dir/baz":        nil,
 				"dir/bar/baz":    nil,
 			})
-			ctx.RegisterModuleType("filegroup",
-				android.ModuleFactoryAdaptor(android.FileGroupFactory))
-			ctx.RegisterModuleType("test",
-				android.ModuleFactoryAdaptor(newTest))
+			ctx.RegisterModuleType("filegroup", android.FileGroupFactory)
+			ctx.RegisterModuleType("test", newTest)
 			ctx.Register()
 
 			_, errs := ctx.ParseBlueprintsFiles("Blueprints")