Implement basic keyboard input

It doesn't support some key combination, but basically works.
It might be an interim solution for a while until evdev is avilable.
And also refactored the code about sending evts to the socket

Bug: 325930433
Bug: 331191129
Test: connect keyboard
Change-Id: I4fb0f62fd705b52b6557737a70575f9769f864e0
diff --git a/virtualizationmanager/src/aidl.rs b/virtualizationmanager/src/aidl.rs
index c5f1ab7..99a0078 100644
--- a/virtualizationmanager/src/aidl.rs
+++ b/virtualizationmanager/src/aidl.rs
@@ -751,6 +751,9 @@
         InputDevice::EvDev(evdev) => InputDeviceOption::EvDev(clone_file(
             evdev.pfd.as_ref().ok_or(anyhow!("pfd should have value"))?,
         )?),
+        InputDevice::Keyboard(keyboard) => InputDeviceOption::Keyboard(clone_file(
+            keyboard.pfd.as_ref().ok_or(anyhow!("pfd should have value"))?,
+        )?),
     })
 }
 /// Given the configuration for a disk image, assembles the `DiskFile` to pass to crosvm.