Fix bug# 2635491: Catch IOException while checking existence of MINI_THUMBNAIL.

http://2635491

Change-Id: I2b39c675f7798711d10c0faea8175124f7beea84

src/com/android/providers/media/MediaThumbRequest.java

@@ -155,6 +155,8 @@ class MediaThumbRequest {
                         pfd = mCr.openFileDescriptor(
                                 mThumbUri.buildUpon().appendPath(c.getString(0)).build(), "r");
                     }
+                } catch (IOException ex) {
+                    // MINI_THUMBNAIL not exists, ignore the exception and generate one.
                 } finally {
                     if (c != null) c.close();
                     if (pfd != null) {