This error will prevent one from rendering out their project for publishing purposes (e.g. Android apk).
The internet reveals that one should edit their CONFIG file found in a given sdk folder of the installation location of Flash Builder. This did not work for me.
SEMILLA SOL APPS SOLUTION:
I got the heap error when working on an Android mobile project. My project had 3 360kbps mp3 files. After some experimentation I reduced those to 128kbps and resolved my issue.
With the CONFIG files edited memory increase, it did not reslove my 360kbps issue of the Java heap error. I still had to reduce my mp3 files. I am currently experimenting with kbps to see what the actual threshold is in this regard. This may actually be a toss up between kbps and length of file...essentially and apparently Flash Builder is not designed to manage larger types of projects...at least in some approach methods (e.g. mobile). Gladly Semilla Sol always discovers a work around.