Revert "Add scripts to generate java APIs used by Mainline modules."

This reverts commit c92380f0.

Reason for revert:
DroidMonitor:

DroidMonitor-triggered revert due to breakage
https://android-build.googleplex.com/builds/quarterdeck?branch=git_master&target=mainline_modules_arm64-userdebug&lkgb=7898389&lkbb=7900541&fkbb=7898474,
bug 205746850

Change-Id: Ibd84dfe68dfe150b7e05b4287364d1946375bf72