Revert "SF: Update InputFlinger outside main thread"

This reverts commit 42a27b5657975485a72033736f37bfe6de0e21a8.

Reason for revert: <Breaking presubmit tests>
Bug: 207839663
Change-Id: Ic066d5a44339128a59e8aa3bb488a41cad13cf76
diff --git a/services/surfaceflinger/BackgroundExecutor.h b/services/surfaceflinger/BackgroundExecutor.h
index 6db7dda..6f6d305 100644
--- a/services/surfaceflinger/BackgroundExecutor.h
+++ b/services/surfaceflinger/BackgroundExecutor.h
@@ -16,7 +16,6 @@
 
 #pragma once
 
-#include <android-base/thread_annotations.h>
 #include <utils/Singleton.h>
 #include <condition_variable>
 #include <mutex>
@@ -34,10 +33,10 @@
 
 private:
     std::mutex mMutex;
-    std::condition_variable mWorkAvailableCv GUARDED_BY(mMutex);
-    bool mDone GUARDED_BY(mMutex) = false;
-    std::vector<std::function<void()>> mTasks GUARDED_BY(mMutex);
+    std::condition_variable mWorkAvailableCv;
     std::thread mThread;
+    bool mDone = false;
+    std::vector<std::function<void()>> mTasks;
 };
 
 } // namespace android