Fix kick_transport test.

Fix broken kick_transport test, and make it not access atransport
internal variables.

Bug: 25935458
Change-Id: I91b4d32a222b2f369f801bbe3903acac9c8ea4f7
(cherry picked from commit 7f27490e7f386401dc38287a67dcb8826e2260c5)
diff --git a/adb/transport.h b/adb/transport.h
index 5857249..35d7b50 100644
--- a/adb/transport.h
+++ b/adb/transport.h
@@ -60,7 +60,13 @@
     int (*read_from_remote)(apacket* p, atransport* t) = nullptr;
     int (*write_to_remote)(apacket* p, atransport* t) = nullptr;
     void (*close)(atransport* t) = nullptr;
-    void (*kick)(atransport* t) = nullptr;
+    void SetKickFunction(void (*kick_func)(atransport*)) {
+        kick_func_ = kick_func;
+    }
+    bool IsKicked() {
+        return kicked_;
+    }
+    void Kick();
 
     int fd = -1;
     int transport_socket = -1;
@@ -82,7 +88,6 @@
     char* device = nullptr;
     char* devpath = nullptr;
     int adb_port = -1;  // Use for emulators (local transport)
-    bool kicked = false;
 
     void* key = nullptr;
     unsigned char token[TOKEN_SIZE] = {};
@@ -123,6 +128,9 @@
     bool MatchesTarget(const std::string& target) const;
 
 private:
+    bool kicked_ = false;
+    void (*kick_func_)(atransport*) = nullptr;
+
     // A set of features transmitted in the banner with the initial connection.
     // This is stored in the banner as 'features=feature0,feature1,etc'.
     FeatureSet features_;