Protect against crash in memory details

Change-Id: Ie80efa04d0c6bc9c117802e5a7018d448f4dc7b8
Fixes: 29308942
diff --git a/src/com/android/settings/applications/ProcessStatsDetail.java b/src/com/android/settings/applications/ProcessStatsDetail.java
index 252b2ef..d538e29 100644
--- a/src/com/android/settings/applications/ProcessStatsDetail.java
+++ b/src/com/android/settings/applications/ProcessStatsDetail.java
@@ -115,6 +115,10 @@
     public void onViewCreated(View view, Bundle savedInstanceState) {
         super.onViewCreated(view, savedInstanceState);
 
+        if (mApp.mUiTargetApp == null) {
+            finish();
+            return;
+        }
         AppHeader.createAppHeader(this,
                 mApp.mUiTargetApp != null ? mApp.mUiTargetApp.loadIcon(mPm) : new ColorDrawable(0),
                 mApp.mUiLabel, mApp.mPackage, mApp.mUiTargetApp.uid);