Remove todo comment from IME tracing proto

This CL removes a TODO comment from the IME trace proto because
there are no current plans of following with it.

Bug: 154348613
Test: nothing to be done
Change-Id: I629c4ced5aa1596be42f5550f5aef3b580ee4ac1

core/proto/android/view/inputmethod/inputmethodeditortrace.proto

@@ -65,8 +65,6 @@ message InputMethodEditorProto {
         repeated ClientSideProto client = 1;
     }
 
-    /* todo: extract as a separate message to allow other dumps to use this as their client side
-        proto */
     /* groups together the dump from ime related client side classes */
     message ClientSideProto {
         optional int32 display_id = 1;