vdexExtractor: Unhide APIs when decompiling files from Android P

Android P runtime is massively modifying the visibility (fields/methods AccessFlags) of many framework classes (https://t.co/PqtZshSzka) via a custom encoding (hiddenapi). vdexExtractor decompiler backend updated to handle & revert this custom encoding https://t.co/xlYwlV0MfD

— Anestis Bechtsoudis (@anestisb) September 8, 2018