GetScreenDPI on Android

[almusx]

Add support for get the screen dpi on android (not the screen scale).

[almusx]

i made this on rcore_android.c:

`int GetScreenDPI(void) {
int dpi = 160;

if (platform.app != NULL && platform.app->config != NULL) {
    dpi = AConfiguration_getDensity(platform.app->config);
}

return dpi;

}`

i got the correct dpi on my device.