uwb: Rewrite implementation of sendUciMessage to use the opened File am: 77971b371b am: db8a7b7c5d am: 3494d6dc1c am: 167ff86e80

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2712294

Change-Id: Ic8063e895940745ca506385da1eed9237ea0dfd7
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>