Fix hotspot notification on old APIs

briar-android/src/main/java/org/briarproject/briar/android/AndroidNotificationManagerImpl.java

@@ -734,7 +734,7 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		}
 		BriarNotificationBuilder b =
 				new BriarNotificationBuilder(appContext, HOTSPOT_CHANNEL_ID);
-		b.setSmallIcon(R.drawable.ic_wifi_tethering);
+		b.setSmallIcon(R.drawable.notification_hotspot);
 		b.setColorRes(R.color.briar_brand_green);
 		b.setContentTitle(
 				appContext.getText(R.string.hotspot_notification_title));
@@ -748,7 +748,8 @@ class AndroidNotificationManagerImpl implements AndroidNotificationManager,
 		i.addFlags(FLAG_ACTIVITY_SINGLE_TOP);
 		i.setAction(ACTION_STOP_HOTSPOT);
 		PendingIntent actionIntent = getActivity(appContext, 0, i, 0);
-		b.addAction(R.drawable.ic_portable_wifi_off, actionTitle, actionIntent);
+		int icon = SDK_INT >= 21 ? R.drawable.ic_portable_wifi_off : 0;
+		b.addAction(icon, actionTitle, actionIntent);
 		notificationManager.notify(HOTSPOT_NOTIFICATION_ID, b.build());
 	}
 

briar-android/src/main/res/drawable-anydpi-v24/notification_hotspot.xml

@@ -0,0 +1,16 @@
+<vector xmlns:android="http://schemas.android.com/apk/res/android"
+	android:width="24dp"
+	android:height="24dp"
+	android:tint="#FFFFFF"
+	android:viewportWidth="24"
+	android:viewportHeight="24">
+	<group
+		android:scaleX="0.92"
+		android:scaleY="0.92"
+		android:translateX="0.96"
+		android:translateY="0.96">
+		<path
+			android:fillColor="@android:color/white"
+			android:pathData="M12,11c-1.1,0 -2,0.9 -2,2s0.9,2 2,2 2,-0.9 2,-2 -0.9,-2 -2,-2zM18,13c0,-3.31 -2.69,-6 -6,-6s-6,2.69 -6,6c0,2.22 1.21,4.15 3,5.19l1,-1.74c-1.19,-0.7 -2,-1.97 -2,-3.45 0,-2.21 1.79,-4 4,-4s4,1.79 4,4c0,1.48 -0.81,2.75 -2,3.45l1,1.74c1.79,-1.04 3,-2.97 3,-5.19zM12,3C6.48,3 2,7.48 2,13c0,3.7 2.01,6.92 4.99,8.65l1,-1.73C5.61,18.53 4,15.96 4,13c0,-4.42 3.58,-8 8,-8s8,3.58 8,8c0,2.96 -1.61,5.53 -4,6.92l1,1.73c2.99,-1.73 5,-4.95 5,-8.65 0,-5.52 -4.48,-10 -10,-10z" />
+	</group>
+</vector>