Add placeholder properties for emulator

Add some placeholder properties in google VHAL. Developers who use the
aae emulator can use them in developing new features without
implementing a real property.

Bug: 193460353
Test: build aae emulator, use adb lshal to change property values
Change-Id: I6131a4892495c4c1e1c73e078572a666a33f984e
Merged-In: I6131a4892495c4c1e1c73e078572a666a33f984e
(cherry picked from commit 4d1fe81bee2a1ef01b1a14638484a2d7528afcc3)
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h
index 7588f70..a3e7606 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/DefaultConfig.h
@@ -1097,6 +1097,42 @@
                                 .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
                         },
         },
+        {
+                .config =
+                        {
+                                .prop = PLACEHOLDER_PROPERTY_INT,
+                                .access = VehiclePropertyAccess::READ_WRITE,
+                                .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
+                        },
+                .initialValue = {.int32Values = {0}},
+        },
+        {
+                .config =
+                        {
+                                .prop = PLACEHOLDER_PROPERTY_FLOAT,
+                                .access = VehiclePropertyAccess::READ_WRITE,
+                                .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
+                        },
+                .initialValue = {.floatValues = {0.0f}},
+        },
+        {
+                .config =
+                        {
+                                .prop = PLACEHOLDER_PROPERTY_BOOLEAN,
+                                .access = VehiclePropertyAccess::READ_WRITE,
+                                .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
+                        },
+                .initialValue = {.int32Values = {0 /* false */}},
+        },
+        {
+                .config =
+                        {
+                                .prop = PLACEHOLDER_PROPERTY_STRING,
+                                .access = VehiclePropertyAccess::READ_WRITE,
+                                .changeMode = VehiclePropertyChangeMode::ON_CHANGE,
+                        },
+                .initialValue = {.stringValue = {"Test"}},
+        },
 #ifdef ENABLE_VENDOR_CLUSTER_PROPERTY_FOR_TESTING
         // Vendor propetry for E2E ClusterHomeService testing.
         {
diff --git a/automotive/vehicle/2.0/default/impl/vhal_v2_0/PropertyUtils.h b/automotive/vehicle/2.0/default/impl/vhal_v2_0/PropertyUtils.h
index d5f6a18..51251a7 100644
--- a/automotive/vehicle/2.0/default/impl/vhal_v2_0/PropertyUtils.h
+++ b/automotive/vehicle/2.0/default/impl/vhal_v2_0/PropertyUtils.h
@@ -189,6 +189,19 @@
     KeyPress = 100,
 };
 
+/**
+ * These properties are placeholder properties for developers to test new features without
+ * implementing a real property.
+ */
+constexpr int32_t PLACEHOLDER_PROPERTY_INT =
+        0x2a11 | VehiclePropertyGroup::VENDOR | VehicleArea::GLOBAL | VehiclePropertyType::INT32;
+constexpr int32_t PLACEHOLDER_PROPERTY_FLOAT =
+        0x2a11 | VehiclePropertyGroup::VENDOR | VehicleArea::GLOBAL | VehiclePropertyType::FLOAT;
+constexpr int32_t PLACEHOLDER_PROPERTY_BOOLEAN =
+        0x2a11 | VehiclePropertyGroup::VENDOR | VehicleArea::GLOBAL | VehiclePropertyType::BOOLEAN;
+constexpr int32_t PLACEHOLDER_PROPERTY_STRING =
+        0x2a11 | VehiclePropertyGroup::VENDOR | VehicleArea::GLOBAL | VehiclePropertyType::STRING;
+
 const int32_t kHvacPowerProperties[] = {
     toInt(VehicleProperty::HVAC_FAN_SPEED),
     toInt(VehicleProperty::HVAC_FAN_DIRECTION),