Drop NDK artifact from sentry-android

[romtsn]

Description

This is a placeholder issue for v9. Once tombstone support is stable, we could:

• Drop the NDK artifact from sentry-android and update docs to mention it's mostly useful when having native libs or Android < 12
• Flip the isTombstoneEnabled flag to true by default

[linear]

JAVA-300

[romtsn]

discuss this beforehand with the GDX team as it affects them likely the most