Move WAPPushManager to /product

WAPPushManager is not in mainline, thus move it to /product.

Bug: 138284376
Test: Boot aosp_cf_x86_phone
Change-Id: I65b530547a25efa501bafcfa986111f0f899211d
diff --git a/packages/WAPPushManager/Android.bp b/packages/WAPPushManager/Android.bp
index 1bec492..c391369 100644
--- a/packages/WAPPushManager/Android.bp
+++ b/packages/WAPPushManager/Android.bp
@@ -9,4 +9,6 @@
     optimize: {
         proguard_flags_files: ["proguard.flags"],
     },
+
+    product_specific: true,
 }