Revert "Revert "Force gtest to use adb unroot if required_root is false or not set""

This reverts commit 1a5eeb3e3573a8f55c75b35c0f24901a607751b5.

Reason for revert: Fix landed in aosp/1122723

Change-Id: I8b487d602d48b9dba35affc8eb31578efd815e52
diff --git a/cc/test.go b/cc/test.go
index 1a0d44f..a5a3680 100644
--- a/cc/test.go
+++ b/cc/test.go
@@ -317,6 +317,10 @@
 	var configs []tradefed.Config
 	if Bool(test.Properties.Require_root) {
 		configs = append(configs, tradefed.Preparer{"com.android.tradefed.targetprep.RootTargetPreparer", nil})
+	} else {
+		var options []tradefed.Option
+		options = append(options, tradefed.Option{"force-root", "false"})
+		configs = append(configs, tradefed.Preparer{"com.android.tradefed.targetprep.RootTargetPreparer", options})
 	}
 	if Bool(test.Properties.Disable_framework) {
 		var options []tradefed.Option