Bootstrap IInputFlingerRust - the Rust component of inputflinger

When inputflinger boots, we create the Rust component of inputflinger,
which we interact with from C++ through the local AIDL interface
IInputFlingerRust.

After we have access to the IInputFlingerRust binder object in C++, all
communication between C++ and Rust can take place purely through AIDL
interfaces.

To initialize the interface, we must first pass a raw pointer to an AIDL
implementation across the language barrier through some other means. In
this CL, we use cxxbridge to bootstrap the local AIDL interface for
IInputFlingerRust.

Bug: 278783893
Test: manual, boot
Change-Id: Ifbd0168ae4fadaa5b357f6064113f1691e6cf5a7