Pass public API list to class2greylist tool.

This is necessary to allow it to exclude synthetic bridge methods from the
generated greylist. We need to be able to apply the @UnsupportedAppUsage
annotation to regular (non-bridged) methods, but due to the SDK visibility
rules, the synthetic bridge is part of the SDK.

Don't do this on build that don't include frameworks/base since the
target is not needed and breaks certain builds.

Bug: 110868826
Test: m
Change-Id: I08f06f38d84945f5473618513c641762bc541e24