Update System default handler title on Bug report handler settings

- Replace "Android System (Shell)" with "Android System"
- https://screenshot.googleplex.com/U3pxUHx3Uv0
- https://screenshot.googleplex.com/qKqqZUJM2w6

Bug: 143017534
Test: Flash device and check the title
Change-Id: I3036520d5887f70d1c43896eda56587d2ff9cdab

src/com/android/settings/development/BugReportHandlerPreferenceController.java

@@ -73,7 +73,7 @@ public class BugReportHandlerPreferenceController extends DeveloperOptionsPrefer
         final String handlerApp = mBugReportHandlerUtil.getCurrentBugReportHandlerAppAndUser(
                 mContext).first;
         if (BugReportHandlerUtil.SHELL_APP_PACKAGE.equals(handlerApp)) {
-            return mContext.getString(R.string.shell_app);
+            return mContext.getString(com.android.internal.R.string.android_system_label);
         }
         ApplicationInfo applicationInfo;
         try {