fix: exclude iOS test harness files from pod sources

Author: thisislvca

packages/react-native-device-activity/ios/ReactNativeDeviceActivity.podspec

@@ -24,4 +24,8 @@ Pod::Spec.new do |s|
   }
 
   s.source_files = "**/*.{h,m,swift}"
+  s.exclude_files = [
+    "Tests/**/*",
+    "TestHarness/**/*"
+  ]
 end