Warn users when selecting non-Direct Boot apps.

Certain apps like Phone, SMS, Emergency Info, and IME are critical
enough that they ideally need to be runnable before the device is
unlocked after a reboot.  Users can still pick non-Direct Boot aware
apps, but this change now warns users that the selected app won't be
runnable until after unlocking.

Bug: 27196876
Change-Id: I0498904d2f664fb41e8c1e6bb30d1cbf437cf4b9

src/com/android/settings/applications/DefaultEmergencyPreference.java

@@ -16,7 +16,6 @@
 
 package com.android.settings.applications;
 
-import android.content.ComponentName;
 import android.content.ContentResolver;
 import android.content.Context;
 import android.content.Intent;
@@ -30,9 +29,11 @@ import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.ArraySet;
 import android.util.AttributeSet;
-import com.android.internal.telephony.SmsApplication;
+
 import com.android.settings.AppListPreference;
+import com.android.settings.R;
 import com.android.settings.SelfAvailablePreference;
+import com.android.settings.Utils;
 
 import java.util.List;
 import java.util.Objects;
@@ -56,6 +57,12 @@ public class DefaultEmergencyPreference extends AppListPreference
         load();
     }
 
+    @Override
+    protected CharSequence getConfirmationMessage(String value) {
+        return Utils.isPackageDirectBootAware(getContext(), value) ? null
+                : getContext().getText(R.string.direct_boot_unaware_dialog_message);
+    }
+
     @Override
     protected boolean persistString(String value) {
         String previousValue = Settings.Secure.getString(mContentResolver,