Added initialization of flite into android build

Added initialization of flite into android build
Also added header file for including flite library
    README.md
    initialize_project.sh
    src/audio/flite.h   (+)
Added Android build files for flite library

Added Android build files for flite library
    external/flite/Android.mk                 (+)
    external/flite/lang/Android.mk            (+)
    external/flite/lang/cmu_us_awb/Android.mk (+)
    external/flite/lang/cmulex/Android.mk     (+)
    external/flite/lang/usenglish/Android.mk  (+)
    external/flite/main/Android.mk            (+)
    external/flite/sdl2-cross-changes.md
    external/flite/src/Android.mk             (+)
    src/Android.mk