Update to Firebase 7.0 and add Installations dependency

FirebaseMLModelDownloader.podspec

@@ -31,7 +31,8 @@ Pod::Spec.new do |s|
   ]
 
   s.framework = 'Foundation'
-  s.dependency 'FirebaseCore', '~> 6.10'
+  s.dependency 'FirebaseCore', '~> 7.0'
+  s.dependency 'FirebaseInstallations', '~> 7.0'
 
   s.pod_target_xcconfig = {
     'GCC_C_LANGUAGE_STANDARD' => 'c99',