AFSK: SCO service fixes, permission

For no apparent reason, the BROADCAST_STICKY permission is needed
on Android 4.x to allow Bluetooth SCO.

AndroidManifest.xml

@@ -10,6 +10,7 @@
 
     <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
     <uses-permission android:name="android.permission.BLUETOOTH" />
+    <uses-permission android:name="android.permission.BROADCAST_STICKY" />
     <uses-permission android:name="android.permission.INTERNET"/>
     <uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
     <uses-permission android:name="android.permission.RECORD_AUDIO" />

src/backend/AfskDemodulator.scala

@@ -55,6 +55,7 @@ class AfskDemodulator(au : AfskUploader, samplerate : Int) extends Thread("AFSK
 			this.join(50)
 		} catch {
 		case e : IllegalStateException => Log.w(TAG, "close(): " + e)
+		case e : NullPointerException => // no recorder yet, ignore.
 		}
 	}
 }

src/backend/AfskUploader.scala

@@ -67,7 +67,11 @@ class AfskUploader(service : AprsService, prefs : PrefsWrapper) extends AprsIsUp
 		if (use_bt) {
 			service.getSystemService(Context.AUDIO_SERVICE)
 				.asInstanceOf[AudioManager].stopBluetoothSco()
-			service.unregisterReceiver(btScoReceiver)
+			try {
+				service.unregisterReceiver(btScoReceiver)
+			} catch {
+				case e : RuntimeException => // ignore, receiver already unregistered
+			}
 		}
 	}