Revert "Reland "Let InputFlinger create the server InputChannel""

Revert submission 12655292-hide-server-input-channel

Reason for revert: b/169173706
Reverted Changes:
Iefbfd9313:Reland "Let InputFlinger create the server InputCh...
I14837d545:Reland "Use new create/removeInputChannel()."

Change-Id: I7db057277df06fd865f5e9ffbdb88c940d0f9e8e
diff --git a/libs/input/android/os/IInputFlinger.aidl b/libs/input/android/os/IInputFlinger.aidl
index 1771d19..0cdf0bb 100644
--- a/libs/input/android/os/IInputFlinger.aidl
+++ b/libs/input/android/os/IInputFlinger.aidl
@@ -30,8 +30,8 @@
     // shouldn't be a concern.
     oneway void setInputWindows(in InputWindowInfo[] inputHandles,
             in @nullable ISetInputWindowsListener setInputWindowsListener);
-    InputChannel createInputChannel(in @utf8InCpp String name);
-    void removeInputChannel(in IBinder connectionToken);
+    void registerInputChannel(in InputChannel channel);
+    void unregisterInputChannel(in IBinder connectionToken);
     /**
      * Sets focus to the window identified by the token. This must be called
      * after updating any input window handles.