Rename the Default* constants in java/config.

These values are used in two out of the many possible sdk_version
configurations, and therefore weren't really defaults in any
meaningful sense. Giving them more descriptive names makes the code
easier to follow.

Bug: 157640067
Test: m nothing
Change-Id: Icf38a9c0be2606ad0478929e1b40dfcee36cddef
diff --git a/java/config/config.go b/java/config/config.go
index bb5be3a..0351009 100644
--- a/java/config/config.go
+++ b/java/config/config.go
@@ -28,12 +28,11 @@
 var (
 	pctx = android.NewPackageContext("android/soong/java/config")
 
-	// TODO(b/157640067): Don't depend on the legacy API by default in the long term.
-	DefaultBootclasspathLibraries = []string{"legacy.core.platform.api.stubs", "core-lambda-stubs"}
-	DefaultSystemModules          = "legacy-core-platform-api-stubs-system-modules"
-	DefaultLibraries              = []string{"ext", "framework"}
-	DefaultLambdaStubsLibrary     = "core-lambda-stubs"
-	SdkLambdaStubsPath            = "prebuilts/sdk/tools/core-lambda-stubs.jar"
+	LegacyCorePlatformBootclasspathLibraries = []string{"legacy.core.platform.api.stubs", "core-lambda-stubs"}
+	LegacyCorePlatformSystemModules          = "legacy-core-platform-api-stubs-system-modules"
+	FrameworkLibraries                       = []string{"ext", "framework"}
+	DefaultLambdaStubsLibrary                = "core-lambda-stubs"
+	SdkLambdaStubsPath                       = "prebuilts/sdk/tools/core-lambda-stubs.jar"
 
 	DefaultJacocoExcludeFilter = []string{"org.junit.*", "org.jacoco.*", "org.mockito.*"}