Don't crash in window manager if we fail getting .apk resources.

This normally shouldn't noramlly happen, but it can in the case of
bug 6647334 (crash in LoadedApk.makeApplication) where the package
manager information becomes inconsistent, and it could also happen
if an app was uninstalled or started updating at just the right
time during a launch.

Bug: 6647334
Change-Id: Iba22efe1d646cdac46099b2135466309577dfa54

Author: Dianne Hackborn

services/java/com/android/server/wm/WindowManagerService.java

@@ -4145,6 +4145,11 @@ public void setAppStartingWindow(IBinder token, String pkg,
             if (theme != 0) {
                 AttributeCache.Entry ent = AttributeCache.instance().get(pkg, theme,
                         com.android.internal.R.styleable.Window);
+                if (ent == null) {
+                    // Whoops!  App doesn't exist.  Um.  Okay.  We'll just
+                    // pretend like we didn't see that.
+                    return;
+                }
                 if (ent.array.getBoolean(
                         com.android.internal.R.styleable.Window_windowIsTranslucent, false)) {
                     return;