specifically this line in
FMODStudio\fmodstudiosrc\lowlevel_api\platforms\android\Makefile
SYSROOT = ${NDK}/platforms/${NDK_32_API}/arch-arm
references a directory structure that has been removed, see this:
https://android.googlesource.com/platform/ndk/+/ndk-release-r16/docs/UnifiedHeaders.md