Remove conditional compilation in app check headers (#8493)

* Remove conditional compilation in app check headers

* Fix missing symbols in build

* throw exception

* update headerdocs

* Revert changes except doc comments

* Update changelog

Author: morganchen12

FirebaseAppCheck/CHANGELOG.md

@@ -1,4 +1,7 @@
-# v8.5.0 -- Unreleased
+# v8.6.0 -- M102
+- [changed] Documented unsupported platforms (#8493).
+
+# v8.5.0 -- M101
 - [changed] App Check SDK available for all supported platforms/OS versions, but App Attest and
 DeviceCheck providers availability changed to match underlying platfrom API availability. (#8388)
 # v8.4.0 -- M100

FirebaseAppCheck/Sources/Public/FirebaseAppCheck/FIRDeviceCheckProvider.h

@@ -16,9 +16,8 @@
 
 #import <Foundation/Foundation.h>
 
-#import "FIRAppCheckProvider.h"
-
 #import "FIRAppCheckAvailability.h"
+#import "FIRAppCheckProvider.h"
 
 #if FIR_DEVICE_CHECK_SUPPORTED_TARGETS
 
@@ -30,6 +29,7 @@ NS_ASSUME_NONNULL_BEGIN
 
 /// Firebase App Check provider that verifies app integrity using the
 /// [DeviceCheck](https://developer.apple.com/documentation/devicecheck) API.
+/// This class is available on iOS, macOS Catalyst, macOS, and tvOS only.
 FIR_DEVICE_CHECK_PROVIDER_AVAILABILITY
 NS_SWIFT_NAME(DeviceCheckProvider)
 @interface FIRDeviceCheckProvider : NSObject <FIRAppCheckProvider>

FirebaseAppCheck/Sources/Public/FirebaseAppCheck/FIRDeviceCheckProviderFactory.h

@@ -28,6 +28,7 @@ NS_ASSUME_NONNULL_BEGIN
 /// `DeviceCheckProvider` for the specified `FirebaseApp` on request. Currently
 /// `DeviceCheckProviderFactory` is the default that will be used by Firebase App Check if no other
 /// provider is specified. See `AppCheck` class for more details.
+/// This class is available on iOS, macOS Catalyst, macOS, and tvOS only.
 FIR_DEVICE_CHECK_PROVIDER_AVAILABILITY
 NS_SWIFT_NAME(DeviceCheckProviderFactory)
 @interface FIRDeviceCheckProviderFactory : NSObject <FIRAppCheckProviderFactory>