Log bouncer prompt reason

Bug: 27434873
Change-Id: I6918507b66506cf95b20f95fe4a5cb19c899122f
diff --git a/packages/Keyguard/src/com/android/keyguard/KeyguardSecurityContainer.java b/packages/Keyguard/src/com/android/keyguard/KeyguardSecurityContainer.java
index 409f6a7..b1d42e7 100644
--- a/packages/Keyguard/src/com/android/keyguard/KeyguardSecurityContainer.java
+++ b/packages/Keyguard/src/com/android/keyguard/KeyguardSecurityContainer.java
@@ -519,6 +519,9 @@
     @Override
     public void showPromptReason(int reason) {
         if (mCurrentSecuritySelection != SecurityMode.None) {
+            if (reason != PROMPT_REASON_NONE) {
+                Log.i(TAG, "Strong auth required, reason: " + reason);
+            }
             getSecurityView(mCurrentSecuritySelection).showPromptReason(reason);
         }
     }