Add a documentation for android llvm aot 
Add a documentation for android llvm aot 

Add a getting started documentation for compiling and running IREE module with dylib-llvm-aot backend
iree-org/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,google/iree,google/iree,iree-org/iree,iree-org/iree,iree-org/iree,google/iree,iree-org/iree,google/iree,google/iree