Accept apex packages as argument.

Bug: 112669193
Test: Successfully reaches PackageManager. Doesn't break existing flows.
Change-Id: If4a173e290ebf0b70beb97111a6d75400da7ec8d
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 0fbeec6..b65d676 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -66,6 +66,7 @@
 const char* const kFeatureStat2 = "stat_v2";
 const char* const kFeatureLibusb = "libusb";
 const char* const kFeaturePushSync = "push_sync";
+const char* const kFeatureApex = "apex";
 
 namespace {
 
@@ -1008,6 +1009,9 @@
     // Local static allocation to avoid global non-POD variables.
     static const FeatureSet* features = new FeatureSet{
         kFeatureShell2, kFeatureCmd, kFeatureStat2,
+#if ADB_HOST
+                kFeatureApex
+#endif
         // Increment ADB_SERVER_VERSION whenever the feature list changes to
         // make sure that the adb client and server features stay in sync
         // (http://b/24370690).