enh: refactor init to use JNI/FFI

packages/flutter/android/src/main/kotlin/io/sentry/flutter/ReplayRecorderCallbacks.kt

@@ -0,0 +1,22 @@
+package io.sentry.flutter
+
+interface ReplayRecorderCallbacks {
+  fun replayStarted(
+    replayId: String,
+    replayIsBuffering: Boolean,
+  )
+
+  fun replayResumed()
+
+  fun replayPaused()
+
+  fun replayStopped()
+
+  fun replayReset()
+
+  fun replayConfigChanged(
+    width: Int,
+    height: Int,
+    frameRate: Int,
+  )
+}