Possible fix for test file not found.

I was not able to repro the issue, so combined all possible fixes:
- "compile_multilib" since the original bug only reproes on 32bit,
- "required" to make sure they are built,
- Android.mk with all-makefiles-under since it's the way it was before I
switched it to .bp-s,

Bug: 194410209
Fixes: 194410209
Test: atest PkgInstallSignatureVerificationTest
Change-Id: I73d7d8b021350b83d32d252b9582b810953a9934
Merged-In: I73d7d8b021350b83d32d252b9582b810953a9934