chore: Invert accessibilityLabel precedence

Author: gabrieldonadel

Libraries/Image/Image.android.js

@@ -187,7 +187,7 @@ const BaseImage = (props: ImagePropsType, forwardedRef) => {
       : null,
     ref: forwardedRef,
     accessible: props.alt !== undefined ? true : props.accessible,
-    accessibilityLabel: props.alt ?? props.accessibilityLabel,
+    accessibilityLabel: props.accessibilityLabel ?? props.alt,
   };
 
   return (

Libraries/Image/Image.ios.js

@@ -156,7 +156,7 @@ const BaseImage = (props: ImagePropsType, forwardedRef) => {
             source={sources}
             internal_analyticTag={analyticTag}
             accessible={props.alt !== undefined ? true : props.accessible}
-            accessibilityLabel={props.alt ?? props.accessibilityLabel}
+            accessibilityLabel={props.accessibilityLabel ?? props.alt}
           />
         );
       }}