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/DefaultPhonePreference.java

@@ -24,22 +24,27 @@ import android.telecom.TelecomManager;
 import android.telephony.TelephonyManager;
 import android.text.TextUtils;
 import android.util.AttributeSet;
+
 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;
 
 public class DefaultPhonePreference extends AppListPreference implements SelfAvailablePreference {
-    private final Context mContext;
-
     public DefaultPhonePreference(Context context, AttributeSet attrs) {
         super(context, attrs);
-
-        mContext = context.getApplicationContext();
         loadDialerApps();
     }
 
+    @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) {
         if (!TextUtils.isEmpty(value) && !Objects.equals(value, getDefaultPackage())) {