Add apexd to base_system.

apexd is a new daemon responsible for managing APEX packages.

Bug: 112455435
Test: apexd is running
Change-Id: I097495af4a6f7374b4d40da4512e3faf517520a1
diff --git a/target/product/base_system.mk b/target/product/base_system.mk
index c2ea1de..26c3ef2 100644
--- a/target/product/base_system.mk
+++ b/target/product/base_system.mk
@@ -27,6 +27,7 @@
     android.test.base \
     android.test.mock \
     android.test.runner \
+    apexd \
     applypatch \
     appops \
     app_process \