Crashlytics remove unnecessary Analytics header (#8269)

We use forward declarations instead, so the header isn't needed. In addition, this was giving errors in the flutter plugin firebase/flutterfire#5900

```
@protocol FIRAnalyticsInterop;
@protocol FIRAnalyticsInteropListener;
```

Author: samedson

Crashlytics/Crashlytics/Controllers/FIRCLSAnalyticsManager.h

@@ -14,8 +14,6 @@
 
 #import <Foundation/Foundation.h>
 
-#import "Interop/Analytics/Public/FIRAnalyticsInterop.h"
-
 NS_ASSUME_NONNULL_BEGIN
 
 @class FIRCLSSettings;