build/soong - support the REL platform version in classpath

Make sure we select the proper API level number for the REL
platform version when generating the classpath protos

Bug: 231272086
Test: build + boot emulator
Change-Id: Ib3b711dc05dd6136a68e6de414d806687a849bc9
diff --git a/java/classpath_fragment.go b/java/classpath_fragment.go
index ca27528..259e977 100644
--- a/java/classpath_fragment.go
+++ b/java/classpath_fragment.go
@@ -131,14 +131,14 @@
 					// TODO(208456999): instead of mapping "current" to latest, min_sdk_version should never be set to "current"
 					if s.minSdkVersion.Specified() {
 						if s.minSdkVersion.ApiLevel.IsCurrent() {
-							jar.minSdkVersion = ctx.Config().LatestPreviewApiLevel().String()
+							jar.minSdkVersion = ctx.Config().DefaultAppTargetSdk(ctx).String()
 						} else {
 							jar.minSdkVersion = s.minSdkVersion.ApiLevel.String()
 						}
 					}
 					if s.maxSdkVersion.Specified() {
 						if s.maxSdkVersion.ApiLevel.IsCurrent() {
-							jar.maxSdkVersion = ctx.Config().LatestPreviewApiLevel().String()
+							jar.maxSdkVersion = ctx.Config().DefaultAppTargetSdk(ctx).String()
 						} else {
 							jar.maxSdkVersion = s.maxSdkVersion.ApiLevel.String()
 						}