Add scripts to generate java APIs used by Mainline modules. This is
aosp/1879177 with fixed build error that caused by dexdeps analyzing
resource only APKs which doesn't contains any .dex files. Now skip the
error generates in that case in gen_java_usedby_apex.sh
Forrest run:https://android-build.googleplex.com/builds/abtd/run/L38900000951898586
Test: TARGET_BUILD_APPS=com.android.adbd m dist apps_only
Change-Id: Id539cbe1b7306ace69c047f95ffc02265a467511
