Don't trigger user activity in screenOnStoppedLw() if the screen is off.

Fixes b/2260437 (device wakes itself back up when camera is last application running)

Change-Id: Icdb3d0369df752a3838fa8e58c7a4bb08efe00a6
Signed-off-by: Mike Lockwood <lockwood@android.com>

policy/com/android/internal/policy/impl/PhoneWindowManager.java

@@ -2221,7 +2221,7 @@ public class PhoneWindowManager implements WindowManagerPolicy {
     }
     
     public void screenOnStoppedLw() {
-        if (!mKeyguardMediator.isShowing()) {
+        if (!mKeyguardMediator.isShowing() && mPowerManager.isScreenOn()) {
             long curTime = SystemClock.uptimeMillis();
             mPowerManager.userActivity(curTime, false, LocalPowerManager.OTHER_EVENT);
         }