[automerger skipped] Merge "Only export boot image files to APEX if they are...

[automerger skipped] Merge "Only export boot image files to APEX if they are actually created" into sc-dev am: 0a796310 -s ours am: cb1c11f8 -s ours

am skip reason: Merged-In I0497a151eb0731cbe6a1a7e7bbbb1e4dda75898f with SHA-1 0788cd60 is already in history

Original change: https://googleplex-android-review.googlesource.com/c/platform/build/soong/+/14703934

Change-Id: Ic90d20dcf49851118153973b507d578c6fad6e46