Added HIDL based software implementation of gatekeeper

This patch adds a HIDL based software implementation of gatekeeper based
on libgatekeeper.

Also adds OWNER files to the vts test and default implementation
directories.

Test: Manually tested in emulator. Changing passwords and login worked.
      VtsHalGatekeeperV1_0TargetTest
      gatekeeper-software-device-unit-tests
Change-Id: I632aeb6677640c133ec1b79e72568840adbc0550
diff --git a/gatekeeper/1.0/software/android.hardware.gatekeeper@1.0-service.software.rc b/gatekeeper/1.0/software/android.hardware.gatekeeper@1.0-service.software.rc
new file mode 100644
index 0000000..60cb96c
--- /dev/null
+++ b/gatekeeper/1.0/software/android.hardware.gatekeeper@1.0-service.software.rc
@@ -0,0 +1,4 @@
+service vendor.gatekeeper-1-0 /vendor/bin/hw/android.hardware.gatekeeper@1.0-service.software
+    class hal
+    user system
+    group system