Fix for Null-dereference read in ixheaacd_init_sbr am: a741e1d5de am: 154faafaa9 am: 969c6ce482 am: 21a96efe69 am: 73a0c8e399

Original change: https://android-review.googlesource.com/c/platform/external/libxaac/+/1425114

Change-Id: Idc9f8ef915d53e33ddd9c9b9169b0006d51d87d3