Log important VrManagerService lifecycle events.

- Events are rare, and user triggered, so will not
  cause logcat spamming.

Change-Id: I2bdf29b0ca7d86ab64e9a20ee018e3f9e8eb1e5d
diff --git a/services/core/java/com/android/server/vr/VrManagerService.java b/services/core/java/com/android/server/vr/VrManagerService.java
index 9a55e7f..2deb0d5 100644
--- a/services/core/java/com/android/server/vr/VrManagerService.java
+++ b/services/core/java/com/android/server/vr/VrManagerService.java
@@ -34,7 +34,6 @@
  */
 public class VrManagerService extends SystemService {
 
-    public static final boolean DEBUG = false;
     public static final String TAG = "VrManagerService";
 
     private final Object mLock = new Object();
@@ -88,7 +87,8 @@
         synchronized (mLock) {
             if (mVrModeEnabled != enabled) {
                 mVrModeEnabled = enabled;
-                if (DEBUG) Slog.d(TAG, "VR mode " + ((mVrModeEnabled) ? "enabled" : "disabled"));
+                // Log mode change event.
+                Slog.i(TAG, "VR mode " + ((mVrModeEnabled) ? "enabled" : "disabled"));
                 onVrModeChangedLocked();
             }
         }