remove unused resources

Signed-off-by: alperozturk <alper_ozturk@proton.me>

app/src/main/res/drawable/nav_notifications.xml

@@ -1,16 +0,0 @@
-<!--
-  ~ Nextcloud - Android Client
-  ~
-  ~ SPDX-FileCopyrightText: 2018-2024 Google LLC
-  ~ SPDX-License-Identifier: Apache-2.0
--->
-<vector xmlns:android="http://schemas.android.com/apk/res/android"
-    android:width="24dp"
-    android:height="24dp"
-    android:tint="#757575"
-    android:viewportWidth="960"
-    android:viewportHeight="960">
-    <path
-        android:fillColor="@android:color/white"
-        android:pathData="M160,760L160,680L240,680L240,400Q240,317 290,252.5Q340,188 420,168L420,140Q420,115 437.5,97.5Q455,80 480,80Q505,80 522.5,97.5Q540,115 540,140L540,168Q620,188 670,252.5Q720,317 720,400L720,680L800,680L800,760L160,760ZM480,880Q447,880 423.5,856.5Q400,833 400,800L560,800Q560,833 536.5,856.5Q513,880 480,880Z" />
-</vector>

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

@@ -11,5 +11,4 @@
     android:id="@+id/toolbar_back_button"
     android:layout_width="match_parent"
     android:layout_height="?attr/actionBarSize"
-    android:background="@color/bg_default"
     app:popupTheme="@style/Theme.AppCompat.DayNight.NoActionBar" />