[flutter_releases] Flutter Stable 2.2.3 Engine Cherrypicks Pt 2 (#27087)

* remove unused variable
diff --git a/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java b/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java
index 843b24e..082fd0a 100644
--- a/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java
+++ b/shell/platform/android/io/flutter/plugin/editing/InputConnectionAdaptor.java
@@ -45,7 +45,6 @@
   private InputMethodManager mImm;
   private final Layout mLayout;
   private FlutterTextUtils flutterTextUtils;
-  private final KeyboardManager keyboardManager;
   private int batchEditNestDepth = 0;
 
   @SuppressWarnings("deprecation")