SimpleDecodingSource:Prevent OOB write in heap mem am: f3590a1b18 am: b240660c2e am: 247199f370

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/16187628

Change-Id: Ic6650ae6aedcdfb0fd2fb7ee2113bd48683edad6