Fix ifdef for android random api

[bnason-nf]

This fixes an Android build failure because getrandom() is not declared. I was specifically using Android NDK 24, and getrandom() was not available in the NDK until version 28.

I am not an export on the Android platform, but based on the thread below it looks like the preferred preprocessor check for Android is __ANDROID__ instead of ANDROID:

https://groups.google.com/g/android-ndk/c/cf9_f1SLXls

However it looks like maybe there are cases where the one without underscores is necessary, so this change just checks for either one. This causes CONFIG_HAS_ARC4RANDOM_BUF to be set to 1 for either Android preprocessor define, and in turn to use arc4random_buf() instead of getrandom().

[bnason-nf]

@wenyongh and @lum1n0us I'm tagging you on this because there was seeming a spurious check failure that I was able to get past with a second essentially no-op commit. Is that a known issue?