VirtualMachine: Clean up input event executor when disconnected

Test: T/H
Change-Id: I9534584ad0f42f1ad1a349731fd1584558bba6f2
diff --git a/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachine.java b/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachine.java
index ad63206..f6cd1cf 100644
--- a/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachine.java
+++ b/libs/framework-virtualization/src/android/system/virtualmachine/VirtualMachine.java
@@ -813,6 +813,10 @@
      */
     @GuardedBy("mLock")
     private void dropVm() {
+        if (mInputEventExecutor != null) {
+            mInputEventExecutor.shutdownNow();
+            mInputEventExecutor = null;
+        }
         if (mMemoryManagementCallbacks != null) {
             mContext.unregisterComponentCallbacks(mMemoryManagementCallbacks);
         }