Check meta before dereferencing it.

Change-Id: Ic8153b33413a34d75a3053dbfb9530a639e0ec12
diff --git a/media/libstagefright/Utils.cpp b/media/libstagefright/Utils.cpp
index 5771c6c..8c5deb3 100644
--- a/media/libstagefright/Utils.cpp
+++ b/media/libstagefright/Utils.cpp
@@ -613,6 +613,9 @@
                       bool isStreaming, audio_stream_type_t streamType)
 {
     const char *mime;
+    if (meta == NULL) {
+        return false;
+    }
     CHECK(meta->findCString(kKeyMIMEType, &mime));
 
     audio_offload_info_t info = AUDIO_INFO_INITIALIZER;