Sunset `sentry-android-okhttp` in favor of `sentry-okhttp`

[romtsn]

Description

Since we have introduced pure jvm sentry-okhttp module in 7.0.0, we need to sunset its predecessor eventually:

### Tasks
- [x] auto-install `sentry-okhttp` instead of `sentry-android-okhttp` when the sdk version is 7.0 and above
- [x] auto-instrument using `io.sentry.okhttp` instead of `io.sentry.android.okhttp` classes when the sdk version is 7.0 and above
- [x] update docs https://docs.sentry.io/platforms/android/integrations/okhttp/

[kahest]

@stefanosiano is this done?