Make the connection between implementation and llndk_library explicit

Instead of assuming a module with the .llndk suffix exists, add an
llndk_stubs property to every cc_library module that has a
corresponding llndk_library.  Also rename the llndk_library to have
an explicit .llndk suffix.

Bug: 170784825
Test: no changes to build.ninja (excluding comments) or Android-${TARGET_PRODUCT}.mk
Change-Id: Ifba79a1ae64a67a9d7393dac2fb012cd8af8e149
diff --git a/libsync/Android.bp b/libsync/Android.bp
index bad6230..4828892 100644
--- a/libsync/Android.bp
+++ b/libsync/Android.bp
@@ -25,6 +25,7 @@
     recovery_available: true,
     native_bridge_supported: true,
     defaults: ["libsync_defaults"],
+    llndk_stubs: "libsync.llndk",
     stubs: {
         symbol_file: "libsync.map.txt",
         versions: [
@@ -34,7 +35,7 @@
 }
 
 llndk_library {
-    name: "libsync",
+    name: "libsync.llndk",
     symbol_file: "libsync.map.txt",
     export_include_dirs: ["include"],
 }