base: Convert libs/services/Android.mk into a blueprint

Convert libs/services/Android.mk into a blueprint module so it can be
linked by other blueprint modules.

Test: mmm frameworks/base
Change-Id: I7acf9aa084d262a5aba5a58e45d9647e15c6dffb

core/java/Android.bp

@@ -3,6 +3,11 @@ filegroup {
     srcs: ["android/security/keymaster/IKeyAttestationApplicationIdProvider.aidl"],
 }
 
+filegroup {
+    name: "IDropBoxManagerService.aidl",
+    srcs: ["com/android/internal/os/IDropBoxManagerService.aidl"],
+}
+
 // only used by key_store_service
 cc_library_shared {
     name: "libkeystore_aidl",