Revert "Let InputFlinger create the server InputChannel"

Revert submission 12594832-hide_server_input_channel

Reason for revert: <INSERT REASONING HERE>
Reverted Changes:
I7033caf10:Use new create/removeInputChannel().
I35f768c8a:Let InputFlinger create the server InputChannel

Bug: 169083114
Bug: 169088136
Change-Id: Ib6945129936006682cd03cea614fbdfd4f5fa008
diff --git a/services/inputflinger/dispatcher/include/InputDispatcherInterface.h b/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
index 67d9a06..c3d50ea 100644
--- a/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
+++ b/services/inputflinger/dispatcher/include/InputDispatcherInterface.h
@@ -18,7 +18,6 @@
 #define _UI_INPUT_INPUTDISPATCHER_INPUTDISPATCHERINTERFACE_H
 
 #include <InputListener.h>
-#include <android-base/result.h>
 #include <android/FocusRequest.h>
 #include <android/os/ISetInputWindowsListener.h>
 #include <input/InputApplication.h>
@@ -156,16 +155,13 @@
      */
     virtual void setFocusedWindow(const FocusRequest&) = 0;
 
-    /**
-     * Creates an input channel that may be used as targets for input events.
+    /* Registers input channels that may be used as targets for input events.
      *
      * This method may be called on any thread (usually by the input manager).
      */
-    virtual base::Result<std::unique_ptr<InputChannel>> createInputChannel(
-            const std::string& name) = 0;
+    virtual status_t registerInputChannel(const std::shared_ptr<InputChannel>& inputChannel) = 0;
 
-    /**
-     * Creates an input channel to be used to monitor input events.
+    /* Registers input channels to be used to monitor input events.
      *
      * Each monitor must target a specific display and will only receive input events sent to that
      * display. If the monitor is a gesture monitor, it will only receive pointer events on the
@@ -173,14 +169,14 @@
      *
      * This method may be called on any thread (usually by the input manager).
      */
-    virtual base::Result<std::unique_ptr<InputChannel>> createInputMonitor(
-            int32_t displayId, bool gestureMonitor, const std::string& name) = 0;
+    virtual status_t registerInputMonitor(const std::shared_ptr<InputChannel>& inputChannel,
+                                          int32_t displayId, bool gestureMonitor) = 0;
 
-    /* Removes input channels that will no longer receive input events.
+    /* Unregister input channels that will no longer receive input events.
      *
      * This method may be called on any thread (usually by the input manager).
      */
-    virtual status_t removeInputChannel(const sp<IBinder>& connectionToken) = 0;
+    virtual status_t unregisterInputChannel(const sp<IBinder>& connectionToken) = 0;
 
     /* Allows an input monitor steal the current pointer stream away from normal input windows.
      *