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/arch_test.go b/android/arch_test.go
index 52a6684..b41e1ab 100644
--- a/android/arch_test.go
+++ b/android/arch_test.go
@@ -338,7 +338,7 @@
 	for _, tt := range testCases {
 		t.Run(tt.name, func(t *testing.T) {
 			ctx := NewTestArchContext()
-			ctx.RegisterModuleType("module", ModuleFactoryAdaptor(archTestModuleFactory))
+			ctx.RegisterModuleType("module", archTestModuleFactory)
 			ctx.MockFileSystem(mockFS)
 			ctx.Register()
 			config := TestArchConfig(buildDir, nil)