[FM] The channel name will not disappear on the main screen after deleting a channel from the Favorites

Enter FM radio -> Tap star icon to add the channel in
the Favorites -> Rename the channel -> Tap star icon
to delete a channel from the Favorites -> Check the name
on the main screen, the channel name will not disappear.

The CL is to fix this issue.

Bug 18847141

from: https://partner-android-review.googlesource.com/#/c/192388/1

Change-Id: Ia8331caa460f3bf0036c3470705e37d8aaf14e5a
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..043a540 100644
--- a/src/com/android/fmradio/FmMainActivity.java
+++ b/src/com/android/fmradio/FmMainActivity.java
@@ -505,6 +505,9 @@
                 // TODO it's on UI thread, change to sub thread
                 if (FmStation.isFavoriteStation(mContext, frequency)) {
                     FmStation.removeFromFavorite(mContext, frequency);
+                    if (mCurrentStation == frequency) {
+                        mTextStationName.setText(FmStation.getStationName(mContext, frequency));
+                    }
                     mButtonAddToFavorite.setImageResource(R.drawable.btn_fm_favorite_off_selector);
                     // Notify scroller
                     mScroller.onRemoveFavorite();
diff --git a/src/com/android/fmradio/FmStation.java b/src/com/android/fmradio/FmStation.java
index 00609e4..5924281 100644
--- a/src/com/android/fmradio/FmStation.java
+++ b/src/com/android/fmradio/FmStation.java
@@ -316,6 +316,7 @@
     public static void removeFromFavorite(Context context, int frequency) {
         ContentValues values = new ContentValues(1);
         values.put(Station.IS_FAVORITE, false);
+        values.put(Station.STATION_NAME, "");
         context.getContentResolver().update(
                 Station.CONTENT_URI,
                 values,