Add E2E tests for Filter blur-with-overflow, drop-shadow, and animated-blur (facebook#55960)

Summary:
Pull Request resolved: facebook#55960

Add E2E tests for the remaining 3 Filter examples in RNTester:
- blur-with-overflow: screenshot test using existing testID
- drop-shadow: screenshot test using existing testID
- animated-blur: interaction test (click button, verify view visible)

Added testID props to Button and Animated.View in AnimatedBlurExample.

Reviewed By: cortinico

Differential Revision: D95353198

fbshipit-source-id: 50528ed929498c89c66210a4984ca7d32d333730

Author: NickGerleman

packages/rn-tester/js/examples/Filter/FilterExample.js

@@ -327,8 +327,10 @@ const AnimatedBlurExample = () => {
       <Button
         onPress={onPress}
         title={isBlurred ? 'Remove Blur' : 'Animate Blur'}
+        testID="animated-blur-button"
       />
       <Animated.View
+        testID="animated-blur-view"
         style={[
           {
             filter: [{blur: animatedValue}],