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/android/path_properties_test.go b/android/path_properties_test.go
index 59bfa6c..c859bc5 100644
--- a/android/path_properties_test.go
+++ b/android/path_properties_test.go
@@ -100,8 +100,8 @@
 			config := TestArchConfig(buildDir, nil)
 			ctx := NewTestArchContext()
 
-			ctx.RegisterModuleType("test", ModuleFactoryAdaptor(pathDepsMutatorTestModuleFactory))
-			ctx.RegisterModuleType("filegroup", ModuleFactoryAdaptor(FileGroupFactory))
+			ctx.RegisterModuleType("test", pathDepsMutatorTestModuleFactory)
+			ctx.RegisterModuleType("filegroup", FileGroupFactory)
 
 			bp := test.bp + `
 				filegroup {