Support for more pods + tests

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

@@ -0,0 +1,10 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+    android:width="24dp"
+    android:height="24dp"
+    android:viewportWidth="24"
+    android:viewportHeight="24"
+    android:tint="?attr/colorControlNormal">
+  <path
+      android:fillColor="@android:color/white"
+      android:pathData="M12,3c-4.97,0 -9,4.03 -9,9v7c0,1.1 0.9,2 2,2h4v-8H5v-1c0,-3.87 3.13,-7 7,-7s7,3.13 7,7v1h-4v8h4c1.1,0 2,-0.9 2,-2v-7C21,7.03 16.97,3 12,3z" />
+</vector>

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

@@ -22,7 +22,7 @@
             app:layout_constraintBottom_toBottomOf="@id/name"
             app:layout_constraintStart_toStartOf="parent"
             app:layout_constraintTop_toTopOf="@id/name"
-            app:srcCompat="@drawable/ic_baseline_earbuds_24" />
+            app:srcCompat="@drawable/ic_device_generic_earbuds" />
 
         <com.google.android.material.textview.MaterialTextView
             android:id="@+id/name"

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

@@ -81,4 +81,5 @@
     <string name="settings_support_email_developer_description">Note that I can only respond in german or english.</string>
     <string name="settings_debug_autoreports_label">Automatic bug reports</string>
     <string name="settings_debug_autoreports_description">Automatically reports issues, e.g. details on an app crash so I can figure out how to fix it.</string>
+    <string name="device_unknown_label">Unknown device</string>
 </resources>