Export SDK library names

A java module exports SDK library names that it is using directly or
indirectly via its dependencies. Manifest fixer uses the SDK lib names
to automatically add <uses-library> tags for the apk.

The SDK library names are exported via exported-sdk-libs file in make.
From Soong, they are exported via LOCAL_EXPORT_SDK_LIBRARIES flag.

Bug: 77575606
Test: m -j

Change-Id: I4e7a9bdc5bf845af85168abf55f8063900bacc72
diff --git a/core/clear_vars.mk b/core/clear_vars.mk
index 8cc7c98..5051ef7 100644
--- a/core/clear_vars.mk
+++ b/core/clear_vars.mk
@@ -84,6 +84,7 @@
 LOCAL_EXPORT_HEADER_LIBRARY_HEADERS:=
 LOCAL_EXPORT_PACKAGE_RESOURCES:=
 LOCAL_EXPORT_PROGUARD_FLAG_FILES:=
+LOCAL_EXPORT_SDK_LIBRARIES:=
 LOCAL_EXPORT_SHARED_LIBRARY_HEADERS:=
 LOCAL_EXPORT_STATIC_LIBRARY_HEADERS:=
 LOCAL_EXTRACT_APK:=