Remove exportable modules when generating snapshots targeting older platform

This change modifies the contents of the generated Android.bp files so
that when generating a snapshot on a older platform, the "exportable"
modules are removed from the bp files, as the "exportable" modules are
first introduced in V and do not exist in older platforms.

Bug: 345162614
Test: ABTD
Change-Id: I2dba51b98deec7805bd796647a66981f237c55a9
diff --git a/sdk/sdk_test.go b/sdk/sdk_test.go
index f9d49d9..4894210 100644
--- a/sdk/sdk_test.go
+++ b/sdk/sdk_test.go
@@ -519,4 +519,140 @@
 		)
 	})
 
+	t.Run("test replacing exportable module", func(t *testing.T) {
+		result := android.GroupFixturePreparers(
+			prepareForSdkTestWithJava,
+			java.PrepareForTestWithJavaDefaultModules,
+			java.PrepareForTestWithJavaSdkLibraryFiles,
+			java.FixtureWithLastReleaseApis("mysdklibrary", "anothersdklibrary"),
+			android.FixtureWithRootAndroidBp(`
+			sdk {
+				name: "mysdk",
+				bootclasspath_fragments: ["mybootclasspathfragment"],
+			}
+
+			bootclasspath_fragment {
+				name: "mybootclasspathfragment",
+				apex_available: ["myapex"],
+				contents: ["mysdklibrary"],
+				hidden_api: {
+					split_packages: ["*"],
+				},
+				core_platform_api: {
+					stub_libs: [
+						"anothersdklibrary.stubs.exportable",
+					],
+				},
+				api: {
+					stub_libs: [
+						"anothersdklibrary",
+					],
+				},
+			}
+
+			java_sdk_library {
+				name: "mysdklibrary",
+				srcs: ["Test.java"],
+				compile_dex: true,
+				min_sdk_version: "S",
+				public: {enabled: true},
+				permitted_packages: ["mysdklibrary"],
+			}
+
+			java_sdk_library {
+				name: "anothersdklibrary",
+				srcs: ["Test.java"],
+				compile_dex: true,
+				min_sdk_version: "S",
+				public: {enabled: true},
+				system: {enabled: true},
+				module_lib: {enabled: true},
+			}
+		`),
+			android.FixtureMergeEnv(map[string]string{
+				"SOONG_SDK_SNAPSHOT_TARGET_BUILD_RELEASE": "S",
+			}),
+			android.FixtureModifyProductVariables(func(variables android.FixtureProductVariables) {
+				variables.BuildFlags = map[string]string{
+					"RELEASE_HIDDEN_API_EXPORTABLE_STUBS": "true",
+				}
+				variables.Platform_version_active_codenames = []string{"UpsideDownCake", "Tiramisu", "S-V2"}
+			}),
+		).RunTest(t)
+
+		CheckSnapshot(t, result, "mysdk", "",
+			checkAndroidBpContents(`
+// This is auto-generated. DO NOT EDIT.
+
+prebuilt_bootclasspath_fragment {
+    name: "mybootclasspathfragment",
+    prefer: false,
+    visibility: ["//visibility:public"],
+    apex_available: ["myapex"],
+    contents: ["mysdklibrary"],
+    api: {
+        stub_libs: ["anothersdklibrary"],
+    },
+    core_platform_api: {
+        stub_libs: ["anothersdklibrary.stubs"],
+    },
+    hidden_api: {
+        annotation_flags: "hiddenapi/annotation-flags.csv",
+        metadata: "hiddenapi/metadata.csv",
+        index: "hiddenapi/index.csv",
+        stub_flags: "hiddenapi/stub-flags.csv",
+        all_flags: "hiddenapi/all-flags.csv",
+    },
+}
+
+java_sdk_library_import {
+    name: "mysdklibrary",
+    prefer: false,
+    visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
+    shared_library: true,
+    compile_dex: true,
+    permitted_packages: ["mysdklibrary"],
+    public: {
+        jars: ["sdk_library/public/mysdklibrary-stubs.jar"],
+        stub_srcs: ["sdk_library/public/mysdklibrary_stub_sources"],
+        current_api: "sdk_library/public/mysdklibrary.txt",
+        removed_api: "sdk_library/public/mysdklibrary-removed.txt",
+        sdk_version: "current",
+    },
+}
+
+java_sdk_library_import {
+    name: "anothersdklibrary",
+    prefer: false,
+    visibility: ["//visibility:public"],
+    apex_available: ["//apex_available:platform"],
+    shared_library: true,
+    compile_dex: true,
+    public: {
+        jars: ["sdk_library/public/anothersdklibrary-stubs.jar"],
+        stub_srcs: ["sdk_library/public/anothersdklibrary_stub_sources"],
+        current_api: "sdk_library/public/anothersdklibrary.txt",
+        removed_api: "sdk_library/public/anothersdklibrary-removed.txt",
+        sdk_version: "current",
+    },
+    system: {
+        jars: ["sdk_library/system/anothersdklibrary-stubs.jar"],
+        stub_srcs: ["sdk_library/system/anothersdklibrary_stub_sources"],
+        current_api: "sdk_library/system/anothersdklibrary.txt",
+        removed_api: "sdk_library/system/anothersdklibrary-removed.txt",
+        sdk_version: "system_current",
+    },
+    module_lib: {
+        jars: ["sdk_library/module-lib/anothersdklibrary-stubs.jar"],
+        stub_srcs: ["sdk_library/module-lib/anothersdklibrary_stub_sources"],
+        current_api: "sdk_library/module-lib/anothersdklibrary.txt",
+        removed_api: "sdk_library/module-lib/anothersdklibrary-removed.txt",
+        sdk_version: "module_current",
+    },
+}
+`),
+		)
+	})
+
 }
diff --git a/sdk/update.go b/sdk/update.go
index afecf9f..0a97fd9 100644
--- a/sdk/update.go
+++ b/sdk/update.go
@@ -480,6 +480,12 @@
 		// Transform the module module to make it suitable for use in the snapshot.
 		module = transformModule(module, snapshotTransformer)
 		module = transformModule(module, emptyClasspathContentsTransformation{})
+
+		targetApiLevel, err := android.ApiLevelFromUserWithConfig(ctx.Config(), s.targetBuildRelease(ctx).name)
+		if err == nil && targetApiLevel.LessThan(android.ApiLevelVanillaIceCream) {
+			module = transformModule(module, replaceExportablePropertiesTransformer{})
+		}
+
 		if module != nil {
 			bpFile.AddModule(module)
 		}
@@ -804,6 +810,50 @@
 	}
 }
 
+type replaceExportablePropertiesTransformer struct {
+	identityTransformation
+}
+
+var _ bpTransformer = (*replaceExportablePropertiesTransformer)(nil)
+
+func handleExportableProperties[T any](value T) any {
+	switch v := any(value).(type) {
+	case string:
+		return java.AllApiScopes.ConvertStubsLibraryExportableToEverything(v)
+	case *bpPropertySet:
+		v.properties = handleExportableProperties(v.properties).(map[string]interface{})
+		return v
+	case []string:
+		result := make([]string, len(v))
+		for i, elem := range v {
+			result[i] = handleExportableProperties(elem).(string)
+		}
+		return result
+	case []any:
+		result := make([]any, len(v))
+		for i, elem := range v {
+			result[i] = handleExportableProperties(elem)
+		}
+		return result
+	case map[string]any:
+		result := make(map[string]any)
+		for k, val := range v {
+			result[k] = handleExportableProperties(val)
+		}
+		return result
+	default:
+		return value
+	}
+}
+
+func (t replaceExportablePropertiesTransformer) transformPropertySetAfterContents(name string, propertySet *bpPropertySet, tag android.BpPropertyTag) (*bpPropertySet, android.BpPropertyTag) {
+	if name == "name" {
+		return propertySet, tag
+	}
+	propertySet.properties = handleExportableProperties(propertySet.properties).(map[string]interface{})
+	return propertySet, tag
+}
+
 func generateBpContents(bpFile *bpFile) string {
 	contents := &generatedContents{}
 	contents.IndentedPrintf("// This is auto-generated. DO NOT EDIT.\n")