LunaEvent: rework sleep event

Make the UI more flexible and
slightly easier to understand.

app/src/main/res/layout/dialog_edit_duration.xml

@@ -29,7 +29,7 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_weight="1"
-            android:text="-5 min"/>
+            android:text="@string/dialog_duration_button_minus_5"/>
 
         <Button
             android:id="@+id/dialog_date_duration_now"
@@ -50,7 +50,7 @@
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:layout_weight="1"
-            android:text="+5 min"/>
+            android:text="@string/dialog_duration_button_plus_5"/>
 
     </LinearLayout>
 

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

@@ -160,8 +160,10 @@
     <string name="dialog_event_detail_notes">Notes</string>
     <string name="dialog_event_detail_signature">by %s</string>
 
-    <string name="dialog_duration_button_now">now</string>
     <string name="dialog_duration_button_asleep">asleep</string>
+    <string name="dialog_duration_button_minus_5">-5 min</string>
+    <string name="dialog_duration_button_now">now</string>
+    <string name="dialog_duration_button_plus_5">+5 min</string>
 
     <string name="dialog_add_logbook_title">Add logbook</string>
     <string name="dialog_add_logbook_logbookname">👶 Logbook name</string>