Support vendor override in default VHAL.

Move vendor override property logic from emulated VHAL to
default VHAL. If system property
"persist.vendor.vhal_init_value_override" is set, then we would
try to parse JSON files in "/vendor/etc/vhaloverride/" and use the
values there to override the default initial values.

Test: unit test
Bug: 193831021
Change-Id: I6823aab3de284d5b1d96186bc9f1325d868fd8d6
diff --git a/automotive/vehicle/2.0/default/Android.bp b/automotive/vehicle/2.0/default/Android.bp
index 2e8ca66..3be460c 100644
--- a/automotive/vehicle/2.0/default/Android.bp
+++ b/automotive/vehicle/2.0/default/Android.bp
@@ -144,7 +144,6 @@
     ],
     whole_static_libs: [
         "android.hardware.automotive.vehicle@2.0-server-common-lib",
-        "android.hardware.automotive.vehicle@2.0-user-hal-helper-lib",
     ],
     static_libs: [
         "android.hardware.automotive.vehicle@2.0-libproto-native",
@@ -213,7 +212,10 @@
         "android.hardware.automotive.vehicle@2.0-default-impl-lib",
         "android.hardware.automotive.vehicle@2.0-libproto-native",
     ],
-    data: [":vhal_test_json"],
+    data: [
+        ":vhal_test_override_json",
+        ":vhal_test_json",
+    ],
     test_suites: ["general-tests"],
 }