ANDROID: pkvm: vmx: Handle interrupt window vmexit

The interrupt window vmexit is handled by the pkvm hypervisor to clear
CPU_BASED_INTR_WINDOW_EXITING. Then return back to the host make request
KVM_REQ_EVENT to inject any pending interrupt.

Bug: 391539939
Test: pKVM works
Upstream-Task: 402758258

Change-Id: Idd970412c68877b59ee84c4258a859077a5613c0
Signed-off-by: Chuanxiao Dong <chuanxiao.dong@intel.com>
Signed-off-by: Dmytro Maluka <dmaluka@google.com>