Revert "Fix WM input limitations on secondary displays (2/N)"

This reverts commit b37e35e4a5576f89a39ff1f422b5c7f71ec3924d.

Reason for revert: null pointer dereference

Change-Id: I009aac84a5c3c4b40fab1c91519252a68272c103
diff --git a/services/core/java/com/android/server/wm/DisplayContent.java b/services/core/java/com/android/server/wm/DisplayContent.java
index 44d0187..4ab06a2 100644
--- a/services/core/java/com/android/server/wm/DisplayContent.java
+++ b/services/core/java/com/android/server/wm/DisplayContent.java
@@ -814,7 +814,9 @@
         // {@link DisplayContent} ready for use.
         mDisplayReady = true;
 
-        mInputMonitor = new InputMonitor(service, mDisplayId);
+        // TODO(b/112081256): Use independent InputMonitor.
+        mInputMonitor = isDefaultDisplay ? new InputMonitor(service, mDisplayId)
+                : mService.getDefaultDisplayContentLocked().mInputMonitor;
     }
 
     boolean isReady() {
@@ -2132,7 +2134,6 @@
             mRemovingDisplay = false;
         }
 
-        mInputMonitor.onRemoved();
         mService.onDisplayRemoved(mDisplayId);
     }