[FM] FM icon will disappear after unmounting SD card

Select "Start Recording" in options menu -> Press "Home"
key -> Enter Settings/Storage/Unmount SD card/OK ->Check
the notification bar after unmounting SD card, FM icon will
disappear after unmounting SD card.

The fix is to add the handling of message
FmListener.LISTEN_RECORDSTATE_CHANGED.

Bug 18861474

From: https://partner-android-review.googlesource.com/#/c/192419/1

Change-Id: I39abee765f6eab77865fb1fdb145fb1fb7eb23fe
Signed-off-by: Benson Huang <benson.huang@mediatek.com>
diff --git a/src/com/android/fmradio/FmMainActivity.java b/src/com/android/fmradio/FmMainActivity.java
index ec7baf0..b29761f 100644
--- a/src/com/android/fmradio/FmMainActivity.java
+++ b/src/com/android/fmradio/FmMainActivity.java
@@ -322,6 +322,12 @@
                     boolean isSpeakerMode = bundle.getBoolean(FmListener.KEY_IS_SPEAKER_MODE);
                     break;
 
+                case FmListener.LISTEN_RECORDSTATE_CHANGED:
+                    if (mService != null) {
+                        mService.updatePlayingNotification();
+                    }
+                    break;
+
                 default:
                     break;
             }