Let genrule have the entrance depend on signapk am: e4c50bf24b

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/+/29733780

Change-Id: I99c67b62d094d298ee498ff61153735d3ca19332
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>
diff --git a/tools/signapk/Android.bp b/tools/signapk/Android.bp
index c799dbf..3010f29 100644
--- a/tools/signapk/Android.bp
+++ b/tools/signapk/Android.bp
@@ -16,7 +16,7 @@
 
 // the signapk tool (a .jar application used to sign packages)
 // ============================================================
-java_library_host {
+java_binary_host {
     name: "signapk",
     srcs: ["src/**/*.java"],
     manifest: "SignApk.mf",