minadbd: statically link libadbd.

Reduce the amount of wasted space on the recovery image by statically
linking all of the adb libraries into minadbd.

Bug: http://b/150317254
Test: booted aosp_walleye-eng into recovery
Change-Id: I5233b1a23c14f9d478bb77c25ebdbb0ce45bcc5a
diff --git a/minadbd/minadbd_services.cpp b/minadbd/minadbd_services.cpp
index eb91fb3..ff91ba9 100644
--- a/minadbd/minadbd_services.cpp
+++ b/minadbd/minadbd_services.cpp
@@ -266,6 +266,10 @@
   }
 }
 
+asocket* daemon_service_to_socket(std::string_view) {
+  return nullptr;
+}
+
 unique_fd daemon_service_to_fd(std::string_view name, atransport* /* transport */) {
   // Common services that are supported both in sideload and rescue modes.
   if (android::base::ConsumePrefix(&name, "reboot:")) {