Move filesystem into Config

The filesystem object was available through ModuleContext.Fs(), but
gives too much access to the filesystem without enforicing correct
dependencies.  In order to support sandboxing the soong_build
process move the filesystem into the Config.  The next change will
make it private.

Bug: 146437378
Test: all Soong tests
Change-Id: I5d3ae9108f120fd335b21efd612aefa078378813

android/namespace_test.go

@@ -633,10 +633,9 @@ func mockFiles(bps map[string]string) (files map[string][]byte) {
 }
 
 func setupTestFromFiles(bps map[string][]byte) (ctx *TestContext, errs []error) {
-	config := TestConfig(buildDir, nil)
+	config := TestConfig(buildDir, nil, "", bps)
 
 	ctx = NewTestContext()
-	ctx.MockFileSystem(bps)
 	ctx.RegisterModuleType("test_module", newTestModule)
 	ctx.RegisterModuleType("soong_namespace", NamespaceFactory)
 	ctx.Context.RegisterModuleType("blueprint_test_module", newBlueprintTestModule)
@@ -644,7 +643,7 @@ func setupTestFromFiles(bps map[string][]byte) (ctx *TestContext, errs []error)
 	ctx.PreDepsMutators(func(ctx RegisterMutatorsContext) {
 		ctx.BottomUp("rename", renameMutator)
 	})
-	ctx.Register()
+	ctx.Register(config)
 
 	_, errs = ctx.ParseBlueprintsFiles("Android.bp")
 	if len(errs) > 0 {