Aws-sdk-ios: AWSLex fails to build in Xcode 12 beta 4

[sebskuse]

Describe the bug

AWSLex fails to build in Xcode 12 beta 4, producing compilation errors.

To Reproduce
Steps to reproduce the behavior:

1. Open the project in Xcode 12
2. Select the AWSLex scheme and build for "Any iOS device"
3. Build
4. See error

Observed Behavior
The framework fails to compile with the message:

/Users/user/test/aws-sdk-ios/AWSLex/AWSLexInteractionKit.m:1003:34: error: expected a type
- (void)requestRecordPermission:(PermissionBlock)response {
                                 ^

Expected Behavior
The framework compiles.
Environment(please complete the following information):

• SDK Version: 2.15.1
• Dependency Manager: Carthage, but issue happens when building via Xcode.
• Swift Version : 5.3
• Xcode Version: 12.0 Beta 4

Additional context

The framework fails to compile on AWSLexInteractionKit.h:519:

- (void)requestRecordPermission:(PermissionBlock)response;

It appears in the iOS 14 SDK PermissionBlock has been removed as a typealias, and replaced with an inline declaration of void (^)(BOOL granted). AWSLexInteractionKit.h should probably be updated to reflect that.

[palpatim]

I believe this will be addressed by https://github.com/aws-amplify/aws-sdk-ios/pull/2868

[palpatim]

We released this in https://github.com/aws-amplify/aws-sdk-ios/releases/tag/2.15.2