Remove isFactoryROM method from PropertyUtil class

host-side edition

bug:125493228
Test: none (not in use)
Change-Id: Idbff737e335165789fa7636e194545cfb594d838
diff --git a/common/host-side/util/src/com/android/compatibility/common/util/PropertyUtil.java b/common/host-side/util/src/com/android/compatibility/common/util/PropertyUtil.java
index 5c6cc71..ab6dac8 100644
--- a/common/host-side/util/src/com/android/compatibility/common/util/PropertyUtil.java
+++ b/common/host-side/util/src/com/android/compatibility/common/util/PropertyUtil.java
@@ -47,12 +47,6 @@
         return propertyEquals(device, BUILD_TYPE_PROPERTY, "user");
     }
 
-    /** Returns whether the device build is the factory ROM */
-    public static boolean isFactoryROM(ITestDevice device) throws DeviceNotAvailableException {
-        // first API level property should be undefined if and only if the product is factory ROM.
-        return device.getProperty(FIRST_API_LEVEL) == null;
-    }
-
     /** Returns whether this build is built with dev-keys */
     public static boolean isDevKeysBuild(ITestDevice device) throws DeviceNotAvailableException {
         String buildTags = device.getProperty(BUILD_TAGS_PROPERTY);