Typo in On Using Keys And Biometrics

[sftim]

Steps to reproduce

On Using Keys and Biometrics has a typo: IsIstance() should be IsInstance()

Expected behavior

No typo

Actual behavior

Typo seen

Notes

https://github.com/mozilla-lockwise/lockwise-android/blob/d3c0511f73c34e8759e1bb597f2d3dc9bcc146f0/docs/architecture/sec-apis.md