Fix UsesLibraryTest for WITH_DEXPREOPT=false

Also, fix testMissingLibrary logic and add some more docs.

Bug: 63081983
Test: cts-tradefed run cts -m CtsAppSecurityHostTestCases --test
android.appsecurity.cts.UsesLibraryHostTest

(cherry picked from commit b7dc1f0e50fb43bb050c258548f5aa2166e74f53)

Change-Id: I219a3033042685ac11f5dd6a6c921f41fb8f7b9b
1 file changed