Remove obsolete RBS files and add missing ones

- Remove sig/lib/appium_lib_core/android/device/network.rbs (no corresponding Ruby file)
- Move sig/lib/appium_lib_core/ios/clipboard.rbs to sig/lib/appium_lib_core/ios/device/clipboard.rbs
- Add sig/lib/appium_lib_core/android/uiautomator2/device.rbs

Co-authored-by: KazuCocoa <5511591+KazuCocoa@users.noreply.github.com>

Author: Copilot

sig/lib/appium_lib_core/android/device/network.rbs

@@ -0,0 +1,11 @@
+module Appium
+  module Core
+    module Android
+      module Uiautomator2
+        module Device
+          def self.extended: (untyped _mod) -> void
+        end
+      end
+    end
+  end
+end

sig/lib/appium_lib_core/android/uiautomator2/device.rbs

@@ -3,13 +3,7 @@ module Appium
     module Ios
       module Device
         module Clipboard
-          include _Bridge
-
-          def execute: (Symbol command, ?Hash[untyped, untyped], ?Hash[untyped, untyped]) -> untyped
-
           def self.add_methods: () -> untyped
-
-          def self.touch_id: -> untyped
         end
       end
     end