I would suggest you aim for the java first, and I will explain why. First consider java:
Java is a good place to begin learning object oriented programming.
Java has been used in the past in many schools as an introductory language and has proven its ability for the novice programmer.
Java can be more involved as you go building on previous experience with the language.
Many open source third-party packages designed as teaching-tools are available through your favorite search engine.
Consider Android:
Android is heavily based on java, but it is much more than that.
Android allows the use of xml to reduce the amount of java code necessary to achieve the same thing. This is a step beyond java.
Android takes java and compiles it to java bytecode as well as dalvik. This is another step beyond just java.
Many of the basics (and advanced for that matter) of android programming are the same as java programming.
So at the end of the day, the more familiar you are with java, the easier it is to learn android. It is not just about learning android either, it is also about knowing what advantages android provides over plain java programming. If you don't know how java does the job, how are you to determine the best way to go in android when it comes to xml or java code? I would consider java a prerequisite to android for these reasons. Not necessarily advanced java, but at least the basics of java.