java_doc rule was using $(location :foo) instead of $(classpath :foo)
macro. This is similar but not the same. The subtle difference is the
replacement that is done for java_library() when only exported deps are
used. While location macro doesn't work here, because there are no out
file associated with such a java_library, classpath macro correctly
resolves the dependencies.
Change-Id: Iab67dff9c332027765bc0da8c46810de11974de8
d9cafb7ca2