Ignore revealKeyguardIfBouncerPrepared request if Bouncer is null.

Conceptually, if the Bouncer is not yet instantiated, it is not prepared
so we should ignore the request.

Test: Existing unit tests passing
Bug: 154928953
Change-Id: Iaa61d65ab8fc056b9ac4566f43599e81a2024e92
diff --git a/packages/CarSystemUI/src/com/android/systemui/car/keyguard/CarKeyguardViewController.java b/packages/CarSystemUI/src/com/android/systemui/car/keyguard/CarKeyguardViewController.java
index 4fde309..197c52d 100644
--- a/packages/CarSystemUI/src/com/android/systemui/car/keyguard/CarKeyguardViewController.java
+++ b/packages/CarSystemUI/src/com/android/systemui/car/keyguard/CarKeyguardViewController.java
@@ -346,6 +346,13 @@
     private void revealKeyguardIfBouncerPrepared() {
         int reattemptDelayMillis = 50;
         Runnable revealKeyguard = () -> {
+            if (mBouncer == null) {
+                if (DEBUG) {
+                    Log.d(TAG, "revealKeyguardIfBouncerPrepared: revealKeyguard request is ignored "
+                                    + "since the Bouncer has not been initialized yet.");
+                }
+                return;
+            }
             if (!mBouncer.inTransit() || !mBouncer.isSecure()) {
                 getLayout().setVisibility(View.VISIBLE);
             } else {