Move KeyMintDevice into its own module

Biometric unlock will also need raw access to the device,
so create a separate module to that end.

Bug: 163866361
Test: keystore2_test

Change-Id: Ia3f10541fa668f606bbcef6df46adfc1ddda5319
diff --git a/keystore2/src/lib.rs b/keystore2/src/lib.rs
index f851d3a..4000b7f 100644
--- a/keystore2/src/lib.rs
+++ b/keystore2/src/lib.rs
@@ -34,6 +34,7 @@
 pub mod metrics;
 pub mod operation;
 pub mod permission;
+pub mod raw_device;
 pub mod remote_provisioning;
 pub mod security_level;
 pub mod service;