Update auto-gen test config template with EXTRA_CONFIGS placeholder

Bug: 134509111
Test: add "require_root: true" to init_benchmarks and libpower_test
build the modules, confirm the extra target preparer is added in the
test config.

Change-Id: I2fdae79d45fd1e5866ee94d1f0e59df106be2a87
diff --git a/core/autogen_test_config.mk b/core/autogen_test_config.mk
index 6d75132..d4ca56f 100644
--- a/core/autogen_test_config.mk
+++ b/core/autogen_test_config.mk
@@ -36,7 +36,7 @@
 $(autogen_test_config_file): PRIVATE_MODULE_NAME := $(LOCAL_MODULE)
 $(autogen_test_config_file) : $(autogen_test_config_template)
 	@echo "Auto generating test config $(notdir $@)"
-	$(hide) sed 's&{MODULE}&$(PRIVATE_MODULE_NAME)&g;s&{EXTRA_OPTIONS}&&g' $< > $@
+	$(hide) sed 's&{MODULE}&$(PRIVATE_MODULE_NAME)&g;s&{EXTRA_CONFIGS}&&g' $< > $@
 my_auto_generate_config := true
 else
 # Auto generating test config file for instrumentation test