Add tests for the Android and iOS plugin

[marandaneto]

Description

Avoid issues such as #1485

• Make the code testable and add unit/and or integration tests for the Kotlin and Swift plugins.
• Add CI step to run the tests

[marandaneto]

Examples https://github.com/getsentry/sentry-react-native/blob/main/RNSentryTester/RNSentryTesterTests/RNSentry%2BinitNativeSdk.mm
https://github.com/getsentry/sentry-react-native/pull/3170/files also adding more tests on Android.
Use the HubAdapter whenever needed to avoid the Static class call which is harder to mock/fake.