Enforce the legacy core/platform API restriction.

This change silently decides whether modules which depend on either
sdkPrivate or sdkCorePlatform get the legacy or the stable version of
the core/platform API, based on whether the module's name is on a
hard-coded list or not.

Test: m java
Test: make a target from the list when its entry is commented out, which correctly fails
Bug: 157640067
Change-Id: I15e5a6c2f07e73718803501d705de0d7ab9bec90

sdk/java_sdk_test.go

@@ -51,10 +51,10 @@ java_system_modules_import {
 	name: "core-current-stubs-system-modules",
 }
 java_system_modules_import {
-	name: "legacy-core-platform-api-stubs-system-modules",
+	name: "stable-core-platform-api-stubs-system-modules",
 }
 java_import {
-	name: "legacy.core.platform.api.stubs",
+	name: "stable.core.platform.api.stubs",
 }
 java_import {
 	name: "android_stubs_current",