Platform mapping-based product config

This allows us to set product variables as build settings instead
of loading them from a target's provider, which further allows us
to read product config variables in transitions.

Bug: 287539062
Bug: 269577299
Test: Presubmits
Change-Id: I8497703f706162572ceb3486240e1eb02a37f5f6
diff --git a/android/config.go b/android/config.go
index fa43962..f95010e 100644
--- a/android/config.go
+++ b/android/config.go
@@ -202,10 +202,10 @@
 // product configuration values are read from Kati-generated soong.variables.
 type config struct {
 	// Options configurable with soong.variables
-	productVariables productVariables
+	productVariables ProductVariables
 
 	// Only available on configs created by TestConfig
-	TestProductVariables *productVariables
+	TestProductVariables *ProductVariables
 
 	// A specialized context object for Bazel/Soong mixed builds and migration
 	// purposes.
@@ -321,7 +321,7 @@
 
 // loadFromConfigFile loads and decodes configuration options from a JSON file
 // in the current working directory.
-func loadFromConfigFile(configurable *productVariables, filename string) error {
+func loadFromConfigFile(configurable *ProductVariables, filename string) error {
 	// Try to open the file
 	configFileReader, err := os.Open(filename)
 	defer configFileReader.Close()
@@ -373,7 +373,7 @@
 
 // atomically writes the config file in case two copies of soong_build are running simultaneously
 // (for example, docs generation and ninja manifest generation)
-func saveToConfigFile(config *productVariables, filename string) error {
+func saveToConfigFile(config *ProductVariables, filename string) error {
 	data, err := json.MarshalIndent(&config, "", "    ")
 	if err != nil {
 		return fmt.Errorf("cannot marshal config data: %s", err.Error())
@@ -402,7 +402,7 @@
 	return nil
 }
 
-func saveToBazelConfigFile(config *productVariables, outDir string) error {
+func saveToBazelConfigFile(config *ProductVariables, outDir string) error {
 	dir := filepath.Join(outDir, bazel.SoongInjectionDirName, "product_config")
 	err := createDirIfNonexistent(dir, os.ModePerm)
 	if err != nil {
diff --git a/android/config_test.go b/android/config_test.go
index 9df5288..7d327a2 100644
--- a/android/config_test.go
+++ b/android/config_test.go
@@ -75,7 +75,7 @@
 
 // run validateConfigAnnotations against each type that might have json annotations
 func TestProductConfigAnnotations(t *testing.T) {
-	err := validateConfigAnnotations(&productVariables{})
+	err := validateConfigAnnotations(&ProductVariables{})
 	if err != nil {
 		t.Errorf(err.Error())
 	}
@@ -88,7 +88,7 @@
 	}
 }
 
-func verifyProductVariableMarshaling(t *testing.T, v productVariables) {
+func verifyProductVariableMarshaling(t *testing.T, v ProductVariables) {
 	dir := t.TempDir()
 	path := filepath.Join(dir, "test.variables")
 	err := saveToConfigFile(&v, path)
@@ -96,20 +96,20 @@
 		t.Errorf("Couldn't save default product config: %q", err)
 	}
 
-	var v2 productVariables
+	var v2 ProductVariables
 	err = loadFromConfigFile(&v2, path)
 	if err != nil {
 		t.Errorf("Couldn't load default product config: %q", err)
 	}
 }
 func TestDefaultProductVariableMarshaling(t *testing.T) {
-	v := productVariables{}
+	v := ProductVariables{}
 	v.SetDefaultConfig()
 	verifyProductVariableMarshaling(t, v)
 }
 
 func TestBootJarsMarshaling(t *testing.T) {
-	v := productVariables{}
+	v := ProductVariables{}
 	v.SetDefaultConfig()
 	v.BootJars = ConfiguredJarList{
 		apexes: []string{"apex"},
diff --git a/android/configured_jars_test.go b/android/configured_jars_test.go
index 32c3613..4b586e4 100644
--- a/android/configured_jars_test.go
+++ b/android/configured_jars_test.go
@@ -21,7 +21,7 @@
 func TestOverrideConfiguredJarLocationFor(t *testing.T) {
 	cfg := NullConfig("", "")
 
-	cfg.productVariables = productVariables{
+	cfg.productVariables = ProductVariables{
 		ConfiguredJarLocationOverrides: []string{
 			"platform:libfoo-old:com.android.foo:libfoo-new",
 			"com.android.bar:libbar-old:platform:libbar-new",
diff --git a/android/fixture.go b/android/fixture.go
index dbc3bc5..6660afd 100644
--- a/android/fixture.go
+++ b/android/fixture.go
@@ -369,7 +369,7 @@
 
 // Allow access to the product variables when preparing the fixture.
 type FixtureProductVariables struct {
-	*productVariables
+	*ProductVariables
 }
 
 // Modify product variables.
diff --git a/android/sdk_version_test.go b/android/sdk_version_test.go
index ea99c4d..30bd002 100644
--- a/android/sdk_version_test.go
+++ b/android/sdk_version_test.go
@@ -75,7 +75,7 @@
 
 	config := NullConfig("", "")
 
-	config.productVariables = productVariables{
+	config.productVariables = ProductVariables{
 		Platform_sdk_version:              intPtr(31),
 		Platform_sdk_codename:             stringPtr("Tiramisu"),
 		Platform_version_active_codenames: []string{"Tiramisu"},
diff --git a/android/test_config.go b/android/test_config.go
index 28d9ec4..2a59d92 100644
--- a/android/test_config.go
+++ b/android/test_config.go
@@ -35,7 +35,7 @@
 	envCopy["PATH"] = os.Getenv("PATH")
 
 	config := &config{
-		productVariables: productVariables{
+		productVariables: ProductVariables{
 			DeviceName:                          stringPtr("test_device"),
 			DeviceProduct:                       stringPtr("test_product"),
 			Platform_sdk_version:                intPtr(30),
diff --git a/android/variable.go b/android/variable.go
index 4442a09..f5dddaf 100644
--- a/android/variable.go
+++ b/android/variable.go
@@ -185,7 +185,7 @@
 
 var defaultProductVariables interface{} = variableProperties{}
 
-type productVariables struct {
+type ProductVariables struct {
 	// Suffix to add to generated Makefiles
 	Make_suffix *string `json:",omitempty"`
 
@@ -489,8 +489,8 @@
 	return &v
 }
 
-func (v *productVariables) SetDefaultConfig() {
-	*v = productVariables{
+func (v *ProductVariables) SetDefaultConfig() {
+	*v = ProductVariables{
 		BuildNumberFile: stringPtr("build_number.txt"),
 
 		Platform_version_name:                  stringPtr("S"),