Packaging: Patch prl files for Android

In the Android packages, there are several .prl files in the lib/ folder. These contain references to the absolute path of the NDK on the build machine. When the reference is to a static library in the NDK, this breaks compilation of user apps, since they will try to link against this non-existent static library.

The prl files need to be patched, and the references to the NDK should be removed from there.