hv: Fix env var used to select protocol

Change-Id: I3b5f4de2d35f6c7fd8ec27bb36c0a4c79b176138
diff --git a/hierarchyviewer2/libs/hierarchyviewerlib/src/com/android/hierarchyviewerlib/device/HvDeviceFactory.java b/hierarchyviewer2/libs/hierarchyviewerlib/src/com/android/hierarchyviewerlib/device/HvDeviceFactory.java
index efc7926..24a5a4f 100644
--- a/hierarchyviewer2/libs/hierarchyviewerlib/src/com/android/hierarchyviewerlib/device/HvDeviceFactory.java
+++ b/hierarchyviewer2/libs/hierarchyviewerlib/src/com/android/hierarchyviewerlib/device/HvDeviceFactory.java
@@ -22,7 +22,7 @@
 
 public class HvDeviceFactory {
     private static final String sHvProtoEnvVar =
-            System.getenv("android.hvproto"); //$NON-NLS-1$
+            System.getenv("ANDROID_HVPROTO"); //$NON-NLS-1$
 
     public static IHvDevice create(IDevice device) {
         // default to old mechanism until the new one is fully tested