Add default implementation for binderized Keymaster HAL and service

The default implementation loads the device's legacy keymaster hal
and wraps in a softkeymasterdevice if the capabilities of the
device is less than keymaster 2.

Test: builds
Bug: 32020919
Change-Id: Ia7e274673b77c2712c386d573715ed3725b0c158
diff --git a/keymaster/3.0/default/android.hardware.keymaster@3.0-service.rc b/keymaster/3.0/default/android.hardware.keymaster@3.0-service.rc
new file mode 100644
index 0000000..86ed1e7
--- /dev/null
+++ b/keymaster/3.0/default/android.hardware.keymaster@3.0-service.rc
@@ -0,0 +1,4 @@
+service keymaster-3-0 /system/bin/hw/android.hardware.keymaster@3.0-service
+    class hal
+    user system
+    group system drmrpc