Add support for hiding the icon in the status bar and the notification on the lockscreen.

This adds proper settings to toggle GB behavior and closes #460.

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/GBApplication.java

@@ -171,6 +171,10 @@ public class GBApplication extends Application {
         return prefs.getBoolean("log_to_file", false);
     }
 
+    public static boolean minimizeNotification() {
+        return prefs.getBoolean("minimize_priority", false);
+    }
+
     static void setupDatabase(Context context) {
         DBOpenHelper helper = new DBOpenHelper(context, DATABASE_NAME, null);
         SQLiteDatabase db = helper.getWritableDatabase();

app/src/main/java/nodomain/freeyourgadget/gadgetbridge/util/GB.java

@@ -61,11 +61,13 @@ public class GB {
                 .setContentText(text)
                 .setSmallIcon(connected ? R.drawable.ic_notification : R.drawable.ic_notification_disconnected)
                 .setContentIntent(pendingIntent)
-                .setPriority(Notification.PRIORITY_MIN)
                 .setOngoing(true);
         if (GBApplication.isRunningLollipopOrLater()) {
             builder.setVisibility(Notification.VISIBILITY_PUBLIC);
         }
+        if (GBApplication.minimizeNotification()) {
+            builder.setPriority(Notification.PRIORITY_MIN);
+        }
         return builder.build();
     }
 

app/src/main/res/values/strings.xml

@@ -65,6 +65,10 @@
 
     <string name="pref_title_language">Language</string>
 
+    <string name="pref_title_minimize_priority">Hide the gadgetbridge notification</string>
+    <string name="pref_summary_minimize_priority_off">The icon in the status bar and the notification in the lockscreen are shown</string>
+    <string name="pref_summary_minimize_priority_on">The icon in the status bar and the notification in the lockscreen are hidden</string>
+
     <string name="pref_header_notifications">Notifications</string>
     <string name="pref_title_notifications_repetitions">Repetitions</string>
     <string name="pref_title_notifications_call">Phone Calls</string>

app/src/main/res/xml/preferences.xml

@@ -30,6 +30,12 @@
             android:entryValues="@array/pref_language_values"
             android:defaultValue="default"
             android:summary="%s" />
+        <CheckBoxPreference
+            android:defaultValue="false"
+            android:key="minimize_priority"
+            android:summaryOff="@string/pref_summary_minimize_priority_off"
+            android:summaryOn="@string/pref_summary_minimize_priority_on"
+            android:title="@string/pref_title_minimize_priority" />
     </PreferenceCategory>
     <PreferenceCategory
         android:key="pref_key_datetime"