Convert __BIONIC__ usages that check for Android to __ANDROID__
Hi all,
As requested in !3987 (comment 2068881) , this PR moves all the Android, non-Bionic specific checks to use the __ANDROID__
preprocessor definition. I followed the guidance in this Google document: https://android.googlesource.com/platform/bionic/+/HEAD/docs/defines.md
The remaining 13 usages seem to address Bionic quirks, and so I did not port them over: bcbaf1be
cc @sdroege