Add mBouncer null checks for view-related requests.

CarKeytuardView is inflated when CarKeyguardView is first started, and
mBouncer is assigned a value onFinishInflated.

Since some of the view-related requests that reference mBouncer could be
called before that event, we need to add null checks for them.

Such a check is redundant for methods that check for mShowing, since if
mShowing is true, it is guaranteed that mBouncer is assigned a value.

Bug: 154928953
Test: Manual and Existing Unit Tests
Change-Id: I796e8bc73459df3b2a0374818556262ebc2ea237

packages/CarSystemUI/src/com/android/systemui/car/keyguard/CarKeyguardViewController.java

@@ -151,7 +151,9 @@ public class CarKeyguardViewController extends OverlayViewController implements
 
     @Override
     public void notifyKeyguardAuthenticated(boolean strongAuth) {
-        mBouncer.notifyKeyguardAuthenticated(strongAuth);
+        if (mBouncer != null) {
+            mBouncer.notifyKeyguardAuthenticated(strongAuth);
+        }
     }
 
     @Override
@@ -204,11 +206,15 @@ public class CarKeyguardViewController extends OverlayViewController implements
 
     @Override
     public void onFinishedGoingToSleep() {
-        mBouncer.onScreenTurnedOff();
+        if (mBouncer != null) {
+            mBouncer.onScreenTurnedOff();
+        }
     }
 
     @Override
     public void onCancelClicked() {
+        if (!mShowing) return;
+
         getOverlayViewGlobalStateController().setWindowFocusable(/* focusable= */ false);
         getOverlayViewGlobalStateController().setWindowNeedsInput(/* needsInput= */ false);
 
@@ -228,6 +234,8 @@ public class CarKeyguardViewController extends OverlayViewController implements
 
     @Override
     public void startPreHideAnimation(Runnable finishRunnable) {
+        if (!mShowing) return;
+
         mBouncer.startPreHideAnimation(finishRunnable);
     }
 
@@ -260,12 +268,12 @@ public class CarKeyguardViewController extends OverlayViewController implements
 
     @Override
     public boolean isBouncerShowing() {
-        return mBouncer.isShowing();
+        return mBouncer != null && mBouncer.isShowing();
     }
 
     @Override
     public boolean bouncerIsOrWillBeShowing() {
-        return mBouncer.isShowing() || mBouncer.inTransit();
+        return mBouncer != null && (mBouncer.isShowing() || mBouncer.inTransit());
     }
 
     @Override