Revert "Revert "use new cmd command""

This reverts commit 3e3b4ec00770258f4e66684addded262dc13003a.

Change-Id: I8bfcd8a2a285f4254539ebca9f70222aa2448ef4
diff --git a/adb/transport.cpp b/adb/transport.cpp
index 7e4f98e..d39b9f7 100644
--- a/adb/transport.cpp
+++ b/adb/transport.cpp
@@ -43,6 +43,9 @@
 
 ADB_MUTEX_DEFINE( transport_lock );
 
+const char* const kFeatureShell2 = "shell_v2";
+const char* const kFeatureCmd = "cmd";
+
 static std::string dump_packet(const char* name, const char* func, apacket* p) {
     unsigned  command = p->msg.command;
     int       len     = p->msg.data_length;
@@ -781,7 +784,8 @@
 const FeatureSet& supported_features() {
     // Local static allocation to avoid global non-POD variables.
     static const FeatureSet* features = new FeatureSet{
-        kFeatureShell2
+        kFeatureShell2,
+        kFeatureCmd
         // 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).