[automerge] libstagefright: fix heap use after free issue 2p: 2bddcbdd0c

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/20068332

Bug: 245242273
Change-Id: I2fd66510bf2cbe57909e9e570cc4cc2617d5beba