Fix Out of Bounds read in TextDescriptions.cpp am: b63d4e785b

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/av/+/18993507

Change-Id: Idbf0bf4b5465be438231ef199cf0f0c6b5a36ea3
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>