The latest Android tooling seems to break the usage with Titanium, because the <android-sdk>/tools/android command is deprecated in favor of the one embedded in Android Studio.
This issue was raised by the community, here are some more details:
I have just updated my Android Studio installation with the latest android tools and now Ti doesn’t recognize the Android sdk anymore on ti info, the platforms list is always empty.
This is likely because /tools/android is deprecated and Google now uses the sdkmanager binary to handle sdk versions. It is really annoying having to maintain 2 separate android sdks on the same machine as it consumes an awful lot of space.