fix: disable Google IMA by default on ios. now shall be enabled in project podfile

react-native-video.podspec

@@ -19,8 +19,15 @@ Pod::Spec.new do |s|
     ss.source_files  = "ios/Video/**/*.{h,m,swift}"
     ss.dependency "PromisesSwift"
 
-    ss.ios.dependency 'GoogleAds-IMA-iOS-SDK', '~> 3.18.1'
-    ss.tvos.dependency 'GoogleAds-IMA-tvOS-SDK', '~> 4.2'
+    if defined?($RNVideoUseGoogleIMA)
+      Pod::UI.puts "RNVideo: enable IMA SDK"
+
+      ss.ios.dependency 'GoogleAds-IMA-iOS-SDK', '~> 3.18.1'
+      ss.tvos.dependency 'GoogleAds-IMA-tvOS-SDK', '~> 4.2'
+      ss.pod_target_xcconfig = {
+        'OTHER_SWIFT_FLAGS' => '$(inherited) -D USE_GOOGLE_IMA'
+      }
+    end
   end
 
   s.subspec "VideoCaching" do |ss|