rust: Add EXTRA_CONFIGS to rust test template

Bug: 200602232
Test: Extra configs are in generated config
Change-Id: I4abd822f970747a176a746c00d0fa5246441f331
diff --git a/core/rust_device_test_config_template.xml b/core/rust_device_test_config_template.xml
index 536f57e..2ab699a 100644
--- a/core/rust_device_test_config_template.xml
+++ b/core/rust_device_test_config_template.xml
@@ -15,6 +15,9 @@
 -->
 <!-- This test config file is auto-generated. -->
 <configuration description="Config to run {MODULE} device tests.">
+
+    {EXTRA_CONFIGS}
+
     <target_preparer class="com.android.tradefed.targetprep.PushFilePreparer">
         <option name="cleanup" value="true" />
         <option name="push" value="{MODULE}->/data/local/tests/unrestricted/{MODULE}" />