InputMethodSubtypeArray: prevent negative count injection am: 1e97361654

Original change: https://googleplex-android-review.googlesource.com/c/platform/frameworks/base/+/30297777

Change-Id: I8a428b0b7b7b72a8c8726113a10a8cd8deebef6d
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>