Avoid ArrayIndexOutOfBoundsException in Wallpaper

SystemUI try to load the wallpaper, but the wallpaper
file size is invalid.
This modification catch ArrayIndexOutOfBoundsException
in Wallpaper.

Flag: EXEMPT small fix
Bug: 369497275
Test: rui
(cherry picked from https://android-review.googlesource.com/q/commit:afc863c8502c52ad65fd8ed747c3592664ad4845)
Merged-In: I857120cee481a7cc1d2058e3ead205e22ae1105c
Change-Id: I857120cee481a7cc1d2058e3ead205e22ae1105c