Pass Config to NewTestContext instead of ctx.Register

Prepare for using Config when adding singletons by passing
Config to NewTestContext and NewContext instead of to ctx.Register.
This will enable a followup change to store SingletonMakeVarsProviders
registered on the Context in the Config, which is necessary to run
multiple tests in parallel without data races.

Test: all soong tests
Change-Id: Id229629a4e42ff4487d317241673837726c075fc
diff --git a/cc/testing.go b/cc/testing.go
index 388a9ce..5a311f4 100644
--- a/cc/testing.go
+++ b/cc/testing.go
@@ -545,8 +545,8 @@
 	return config
 }
 
-func CreateTestContext() *android.TestContext {
-	ctx := android.NewTestArchContext()
+func CreateTestContext(config android.Config) *android.TestContext {
+	ctx := android.NewTestArchContext(config)
 	ctx.RegisterModuleType("cc_fuzz", FuzzFactory)
 	ctx.RegisterModuleType("cc_test", TestFactory)
 	ctx.RegisterModuleType("cc_test_library", TestLibraryFactory)