chore(android): Remove dead code, cold start bool is now always present

Author: krystofwoldrich

flutter/android/src/main/kotlin/io/sentry/flutter/SentryFlutterPlugin.kt

@@ -147,9 +147,6 @@ class SentryFlutterPlugin : FlutterPlugin, MethodCallHandler, ActivityAware {
     if (appStartTime == null) {
       Log.w("Sentry", "App start won't be sent due to missing appStartTime")
       result.success(null)
-    } else if (isColdStart == null) {
-      Log.w("Sentry", "App start won't be sent due to missing isColdStart")
-      result.success(null)
     } else {
       val appStartTimeMillis = DateUtils.nanosToMillis(appStartTime.nanoTimestamp().toDouble())
       val item = mapOf<String, Any?>(