style(lint): narrowing a property type in subclass requires compiler consent

you need to inform the Xcode compiler that you are not intending to reimplement
the setters/getters for the property (i.e., '@synthesize'), you just want a
narrower type, so you need to mark them as '@dynamic'

Author: mikehardy

ios/RNGoogleMobileAds/RNGoogleMobileAdsMediaView.h

@@ -30,6 +30,7 @@ NS_ASSUME_NONNULL_BEGIN
 #ifdef RCT_NEW_ARCH_ENABLED
 @interface RNGoogleMobileAdsMediaView : RCTViewComponentView
 
+// this setters/getters here are provided by RCTViewComponentView super, we just narrow the type.
 @property(nonatomic, strong, nullable) GADMediaView *contentView;
 #else
 @interface RNGoogleMobileAdsMediaView : GADMediaView

ios/RNGoogleMobileAds/RNGoogleMobileAdsMediaView.mm

@@ -48,6 +48,8 @@ @implementation RNGoogleMobileAdsMediaView {
 #ifdef RCT_NEW_ARCH_ENABLED
 #pragma mark - Fabric specific
 
+@dynamic contentView;  // provided by superclass, but we narrow the type in our declaration
+
 - (instancetype)initWithFrame:(CGRect)frame {
   if (self = [super initWithFrame:frame]) {
     static const auto defaultProps = std::make_shared<const RNGoogleMobileAdsBannerViewProps>();

ios/RNGoogleMobileAds/RNGoogleMobileAdsNativeView.h

@@ -30,6 +30,7 @@ NS_ASSUME_NONNULL_BEGIN
 #ifdef RCT_NEW_ARCH_ENABLED
 @interface RNGoogleMobileAdsNativeView : RCTViewComponentView
 
+// provided by superclass, but we narrow the type in our declaration
 @property(nonatomic, strong, nullable) GADNativeAdView *contentView;
 #else
 @interface RNGoogleMobileAdsNativeView : GADNativeAdView

ios/RNGoogleMobileAds/RNGoogleMobileAdsNativeView.mm

@@ -50,6 +50,8 @@ @implementation RNGoogleMobileAdsNativeView {
 #ifdef RCT_NEW_ARCH_ENABLED
 #pragma mark - Fabric specific
 
+@dynamic contentView;  // provided by superclass, but we narrow the type in our declaration
+
 - (instancetype)initWithFrame:(CGRect)frame {
   if (self = [super initWithFrame:frame]) {
     static const auto defaultProps = std::make_shared<const RNGoogleMobileAdsNativeViewProps>();