look at Java 7 compared to Lua:
Why does the Java port of Quake 2 (Jake 2) benchmark at the same level as the official C version of the game on the same hardware?
Why do super high volume sites like Twitter run primarily on a Java centric back end. They usually have extremely fast response times with extremely large volumes of data. Their code is actually Scala from what they say, but that runs on a Java VM.
If you mean real time in the sense that you can have more formal proofs of low response times there is even http://www.rtsj.org/
Also, Android does support C/C++ development. They also have Renderscript which is a C-family language.
Also, if you want PS3 level graphics or better you need to upgrade from a Tegra 3 chipset. There is no way a programming language is going to get around that.